IN 1976, Clyde's restaurant had to replace 17,000 ashtrays. At $1.06 an ashtray, that's more than $18,000 worth of glass. By and large they didn't break, figured Clyde's; when the restaurant switched to cheaper ashtrays, the disappearances were cut in half.

They'd been stolen.

Most of Washington's restaurant thieves are not slithery burglars in black leather gloves, nor are they kleptomaniacs driven to taking unwatched creamers. They are souvenir hunters, young people, grown people and often well-to-do people. Whatever their profiles, though, they have one common trait: they usually get away with it--and sometimes with a lot of it. "People will steal anything and everything they can get out the door," said a manager from Alexandria's Fish Market.

The restaurateur often does not notice the theft until after the patron leaves, or if a patron pays for a $100 dinner with an American Express Gold Card and then sneaks off with a salt shaker, the manager usually decides it's not worth the hassle or confrontation. In other cases, the restaurateur will let a thief slide because the ashtray that lands on a coffee table in Cleveland may be good advertising for him. All he asks, said Giulio Santillo, owner of Tiberio, is "if somebody asks you where you stole it from, tell them Tiberio."

There is evidence of a snitcher in many of us; the motel towel that ends up waxing the car, the college cafeteria knives heisted in the knapsack to the dorm room. But that is tyros' booty. Washington's restaurant thieves are ritzy. Restaurateurs report losses of Villeroy & Boch china ashtrays from Il Giardino, Belgian linen tablecloths and handmade Chinese porcelain vases from Clyde's of Tysons Corner, Givenchy hand lotion from the ladies' restroom at Tiberio.

Size does not deter the Washington restaurant thief, either. A 3-by-5 foot oriental rug was rolled out of the Foundry's foyer a few years ago. Every summer, the Trio loses about a half dozen chairs from its outdoor patio, said owner George Mallios. And at the Round Table, Mallios' other restaurant, an 8-foot rubber plant disappeared shortly after the restaurant opened.

Mug shots of spoon stealers do not hang in restaurant vestibules, but according to William Jepsen, assistant general counsel of the D.C. police department, an individual caught stealing from a restaurant could be charged with "theft in the second degree" and, if convicted, could land in jail for a maximum of one year or made to pay a maximum fine of $1,000--or both. That's if the goods lifted are worth less than $250. If the heist is hefty (a table setting of Lenox china?)--worth more than $250--the charge goes to a maximum of $5,000, the penalty to 10 years maximum imprisonment or both.

Landing behind bars for pocketing a sugar bowl is unlikely, however. Dimitri Mallios, brother of restaurateur George Mallios, and a Washington attorney whose clients are primarily restaurateurs, said he doesn't know of any restaurants that have prosecuted patrons for stealing. "Most restaurants don't even prosecute people who run out on a check," said Mallios.

A restaurateur who catches a thief with more than a sugar bowl may feel differently, though. Pat Haley, co-owner of Gary's restaurant, said that if he had spotted the person who stole an oriental rug from the restaurant's ladies' room, "I would prosecute her. When they're taking something of real value, then we have to do it."

In rare cases, restaurateurs will call the police, said Lt. Steven Mairoca of the Second District, a 20-year veteran of the D.C. police department. But by the time the police show up, the patrons will have "discarded the property they were accused of taking," he said. Usually, said Mairoca, restaurateurs would rather handle the issue themselves. They "don't want the publicity," he explained.

While all restaurants are potential targets, some are more obvious than others, depending on the renown of the table accessories (the 32-ounce beer schooners at the Fish Market), the ease in stealing them (silver demitasse spoons are a popular pocket item) or the need (condiments and salt and pepper shakers were often-missed staples at the Trio when that area was filled with rooming houses in the '60s). "Whatever's not tied down, you have to worry about losing," said the Trio's Mallios.

And sometimes whatever is tied down. Even though they're attached to the tables with metal chains, the art-deco penguin vases at F. Scott's get literally ripped off. "We see people slowly working on them," said Peter Yaffe, general manager of 1789, Inc. And the outside logo doormat at Les Ambassadeurs (when it was called Rive Gauche) was once stolen, even though it was glued to the pavement.

Confronting a suspect may not be an easy task for a restaurateur. Some, like F. Scott's Yaffe, said his staff breaks the news to thieves with "something peaceful," like, "You're welcome to buy the penguin vase , but you can't take it with you." Other restaurateurs get right to the point: "You don't have to be diplomatic," said the Fish Market's spokesman. "When you see someone stealing your car, you don't have to be polite."

Getting caught in the act can elicit either of two reactions from a restaurant thief: embarrassment ("I have embarrassed the hell out of people," said Clyde's bartender Wayne Brem, when he confronts ashtray stealers with, "So, what's the deal?") or offense (At Clyde's in Tysons Corner, a group of 10 people decided "they were going to take half their table with them," about $200 worth of goods, said Robert Daniels, then-manager of the Virginia location. One man who had a tablecloth hanging out of his coat became very irate, said Daniels, when he confronted him. His party had spent $400 there on food, retorted the diner).

And then there's the feeble alibi. Spotting a man walking out with paintings from the Round Table's wall, co-owner Gus Ladas, who questioned the thief, was told he was "taking them out to be cleaned." Or maybe the truth: When the waiters at the Foundry confront diners whose floral centerpieces have disappeared, said owner David Middleton, responses range from, "They weren't here when we sat down," to, "I wanted it for my mother."

After new restaurants with fancy table accessories open, they frequently learn the hard way. The latest example is Mr. K's, the swish new Chinese restaurant on K Street. According to manager Everett Phak, since the restaurant opened in late February, it has already lost "quite a few," of its sterling Taiwanese chopstick holders. As a result, if waiters see the $20 holders missing, they are instructed to tell parties: "This is not a souvenir, please leave it on the table."

Restaurateurs can retaliate against patrons in more subtle ways. At Chez Froggy, owner Pierre Desplechin once added $5 onto a woman's credit card bill. "What's the extra charge?" she called and asked him when she received her monthly statement. "For the placemats and flowerpots you stole," he answered. Later, she called this newspaper to complain. No, said the admitted placemat-thief indignantly, she hadn't stolen any flowerpots.

Sometimes the theft can be an inside job. Daniels said that when some omelet pans disappeared from Clyde's, it was not due to customers. The pans, he said, "may have graced the kitchens of some of our ex-cooks." In addition, there are equipment losses in a restaurant that can be attributed to neither the patrons nor the staff. Every year Il Giardino buys "a lot" of new silverware, said manager Mario Fazio. But, said Fazio, " you can't say people steal it. Some goes into the trash."

The most common carrier of stolen goods, agreed restaurateurs interviewed, is the pocketbook. ("We will see a thin purse come in and a bulging purse go out," said F. Scott's Yaffe.) But there are other modus operandi. As a woman was walking toward the ladies' room in the former Rive Gauche, a silver ramasse miette (the scraper used to remove crumbs from the table) fell out of her blouse--right in front of the maitre d', reported chef Michel Laudier. A Washingtonian dining in New York noticed his host strapping a pepper mill in an umbrella. Even though it was raining outside, "the umbrella kept closed for about two blocks," he said.

For some restaurateurs, it can turn into a battle of wits. He thinks of deterrents and the thief tries to outdo him. At Tiberio, for example, the Chanel No. 5 in the ladies' room sits on the counter without its top, making it difficult to pocket. Even so, Santillo said, women have crumpled paper towels, "stopped it up" and taken the bottle anyway.

And at Les Ambassadeurs, Laudier jokingly said he was thinking of printing on the menu: "The espresso spoon is not like a pill; do not take one after each meal," because the spoons disappear so frequently.

The Foundry's Middleton said that this year's recession had made the monetary loss from thefts "become very important." It's hard to budget for it, too, said Middleton, "because you don't know what or how much you're going to miss."

Why, then, do people who would never think of stealing from a store suddenly become restaurant Robin Hoods? Some restaurateurs concluded that patrons think there's nothing wrong with it; diners see the restaurant as a rich enterprise that won't miss the ashtrays, or they feel that since they paid a lot of money for dinner, they're somehow entitled to the coffee cup. In addition, diners--or restaurateurs--may not even think of it as stealing. Tiberio's Santillo likes to refer to it as "collecting." Sichuan Garden's Raymond Tam allows banquet diners to take the chopstick holders and chopsticks because he "would like them to have that souvenir," although he has stopped putting them out on the regular lunch and dinner tables. (Tam estimated that with the restaurant's daily average of 500 customers, it would lose about "300 a day.")

According to speculation by Dr. Ralph Wittenberg, a psychiatrist who heads the public information committee of the Washington Psychiatric Society, the restaurant thief derives "very intense unconscious gratification" from the act. "It represents something special, like you've had a piece of the rock," said Wittenberg. In addition, hypothesized Wittenberg, since restaurants "lend themselves to parental transfer--they feed you, they take care of you," this attention can induce childlike behavior. The "boundaries between what's theirs the patrons' and somebody else's becomes blurry," he said. " You get an expansive view that everything there is for you."

Some thieves may even get satisfaction out of boasting about their exploits. Witness: One traveling salesman, who has built a 20-year history of stealing from restaurants, rationalizes his theft as retaliation for bad service. Once he stole bar signs from a Connecticut restaurant after spotting a cockroach on his plate. Another time he stole a wreath from a restaurant's door after the bartender accused him of trying to pocket a glass he said he had no intention of stealing. Among his more outrageous capers was the time he claimed to have grabbed the display steaks at a Louisville restaurant to use later for a barbecue.

For others, there's the temptation of just wanting something. One man who admitted he stole a white bakelite ashtray from the A.V. Ristorante on New York Avenue said he did so simply because "it is a real piece of Washingtoniana, too ugly to buy but too remarkable to live without."