It was evening rush hour on Valentine's Day. Even though many people had not come to work that day because of the big snow, the Virginia-bound Metro had its usual wall-to-wall crowds.

A reader of mine from Fairfax was one of the last people to wedge her way onto the train at Farragut West. She had to stand, of course. And as soon as the train left the station, "I immediately felt someone behind me pressing just a little too close.

"I tried to move forward to give this person some room, but every time I did, he was right on my back," my correspondent writes. "I was pretty sure after a few minutes of moving to accommodate this jerk that there was no way the train could be that crowded . . . "

So our heroine elbowed the guy in the ribs -- not viciously, but hard enough to separate him from her. However, it was only half a solution, because "we arrived at another station, and with some more jostling, he positioned himself behind another woman.

" . . . Sure enough, she kept trying to look over her shoulder and see what was going on. Obviously, he was doing the same thing to her."

The second victim finally ducked away from the man, whereupon he "moved himself behind another woman and proceeded to do the same thing to her." When Victim Number Three didn't react immediately, "he leaned his head into her hair and smelled it."

That was enough for my correspondent. She reached over, yanked on the man's sweater and said: "Why don't you back up a couple of steps and give the girl some room?"

To which he replied, "She can tell me to step back if she wants to."

To which my correspondent replied, "I'm telling you to step back. Get off her back now!"

For the rest of the trip, my correspondent says, "the jerk behaved himself."

Now, I think my correspondent deserves the cheers of everyone of us. In an era of "don't get involved," she got very involved -- and stopped a weirdo in his tracks. She probably didn't convince this wonderful human being to abandon his sick tricks forever. But I'll bet he thinks twice before he tries it again.

However, my correspondent is also thinking twice. She says she has been dismayed by the reaction of her friends and relatives. Everyone of them who has heard the story "feels I shouldn't have said anything to this guy. They said there's no telling what he could have done."

One friend's reaction was particularly galling to my reader. The friend said that as soon as the man moved on to the second woman, "it ceased to be my problem any more.

"I don't understand thinking like that," my correspondent writes. "All I waited for was the assurance in my own mind that he was doing what I thought he was doing . . . I was not going to ride home with the regret that I should have said something and hadn't."

My guess is that very few women -- and very few men, for that matter -- would have said anything to El Creepo. I doubt that many people would have elbowed the guy away, either. My nose tells me that most people would have moved away from him as quickly and as silently as possible, like the second victim on Feb. 14.

It's not just a question of risking a punch or a gunshot. It's a matter of looking ridiculous, or being wrong.

I'll bet most Creepos, confronted like this one was, would turn all innocence and outrage. "Are you suggesting that I molested you?" they'd shout. And suddenly the accuser would have to wonder whether those contacts might have been caused by the close quarters of a rush hour subway car after all. The accuser might even be sued for slander.

Still, that's a risk I'd be willing to run. If fisticuffs or other violence had started, I'm sure someone in the car would have come to the aid of my correspondent. Whether you're male or female, I'm sure you couldn't stand by and watch a man assault a woman without trying to break it up. Meanwhile, I doubt that a slander suit based on an insult in a subway car would get to first base.

The long and the short of it is that my friend from Fairfax did exactly what she should have done. If just one passenger feels safer on the subway because of what she did, it will have been worth it.