It is Saturday, Shopping Saturday, as it's called by the merchants who spread their wares like plush welcome mats across the pages of my newspaper.

But the real market I discover is a different, less eager place than the one I read about. On this Shopping Saturday I don't find welcomes, I find warnings and wariness.

At the first store, a bold sign of the times confronts me: "Shoplifters Will Be Prosecuted to the Full Extent of the Law."

At the second store, instead of a greeter, I find a doorkeeper. It is his job, his duty, to bar my entrance. To pass, I must give up the shopping bag on my arm. I check it in and check it out.

At the third store, I venture as far as the dressing room. Here I meet another worker paid to protect the merchandise rather than to sell it. The guard of this dressing room counts the number of items I carry in and will count the number of items I carry out.

In the mirror, a long, white, plastic security tag juts out from the blouse tucked into the skirt. I try futilely to pat it down along my left hip; try futilely to zip the skirt.

Finally, during these strange gyrations, a thought seeps through years of dulled consciousness, layers of denial. Something has happened to the relationship between shops and shoppers. I no longer feel like a woman in search of a shirt. I feel like an enemy at Checkpoint Charlie.

I finally, belatedly, realize that I am treated less like a customer these days and more like a criminal. And I hate it. This change happened gradually, and understandably. Security rose in tandem with theft. The defenses of the shopkeepers went up, step by step, with the offenses of the thieves.

But now as the weapons escalate, it's the average consumer, the innocent bystander, who is hit by friendly fire.

I don't remember the first time an errant security tag buzzed at the doorway, the first time I saw a camera eye in a dress department. I accepted it as part of the price of living in a tight honesty market.

In the supermarket, they began to insist on a mug shot before they would cash my check. I tried not to take it personally. At the drug store, the cashier began to steple my bags closed. And I tried not to take it personally.

Now, these experiences have accumulated until I feel routinely treated like a suspect. At the jewelry store, the door is unlocked only for those who pass judgment. In the junior department, the suede pants are permanently attached to the hangers. In the gift shop, the cases are only opened with a key.

I am not surprised anymore, but I am finally aware of just how unpleasant it is to be dealt with as guilty until we prove our innocence. Anyplace we are not known, we are not trusted. The old slogan, "Let the Consumer Beware," has been replaced with a new slogan: "Beware of the Consumer."

It is no fun to be Belgium in the war between sales and security. Thievery has changed the atmosphere of the marketplace. Merchant distrust has spread through the ventilation system of a whole business, a whole city, and it infects all of us.

At the cashier counter today, with my shirt in hand. I the Accused stand quietly while the saleswoman takes my credit card I watch her round up the usual suspicions. In front of my face, without a hint of embarrassment, she checks my charge number against the list of stolen credit vehicles. While I stand there, she calls the clearinghouse of bad debtors.

Having passed both tests, I am instructed to add my name, address, serial number to the bottom of the charge. She checks one signature against another, the picture against the person. Only then does she release the shirt into my custody.

And so this shopping Saturday I take home six ounces of silk and a load of resentment.