...Meg Daniel presses zero whenever she hears a computerized operator on the telephone so that she can talk to a real person. "Just because they want a computer to handle me doesn't mean I have to play along," she said.

When subscription cards fall from magazines Andrew Kirk is reading, he stacks them in a pile at the corner of his desk. At the end of each month, he puts them in the mail but leaves them blank so that the advertiser is forced to pay the business reply postage without gaining a new subscriber.

[...]

Wesley A. Williams spent more than a year exacting his revenge against junk mailers. When signing up for a no-junk-mail list failed to stem the flow, he resorted to writing at the top of each unwanted item: "Not at this address. Return to sender." But the mail kept coming because the envelopes had "or current resident" on them, obligating mail carriers to deliver it, he said.

Next, he began stuffing the mail back into the "business reply" envelope and sending it back so that the mailer would have to pay the postage. "That wasn't exacting a heavy enough cost from them for bothering me," said Mr. Williams, 35, a middle school science teacher who lives in Melrose, N.Y., near Albany.

After checking with a postal clerk about the legality of stepping up his efforts, he began cutting up magazines, heavy bond paper, and small strips of sheet metal and stuffing them into the business reply envelopes that came with the junk packages.

"You wouldn't believe how heavy I got some of these envelopes to weigh," said Mr. Williams, who added that he saw an immediate drop in the amount of arriving junk mail. A spokesman for the United States Postal Service, Gerald McKiernan, said that Mr. Williams's actions sounded legal, as long as the envelope was properly sealed.