So, you know how charities, when they write to ask you for money, will enclose an envelope for your contribution? Most of them use postpaid envelopes, marked "postage to be paid by addressee." A few of them don't provide postage at all: they write in the spot where the stamp is supposed to go, "Your first-class stamp will help us devote more funds to our programs!" (as if that 42 cents was going to make all the difference to them). But a few of them enclose envelopes with actual stamps on them. Maybe they're hoping that you'll figure, "Gee, I guess I might as well send them a check rather than throw away a perfectly good stamp."
I never fell for that, but I did hate throwing away the stamped envelopes. I used to return them to the post office for a credit, but the last time I tried this, they told me they wouldn't accept them anymore. So then I got a brilliant idea: instead of returning the stamp, I would reuse the whole envelope, by just pasting a blank label over the address of the organization and re-addressing it. I figured there was nothing dishonest about this: after all, I couldn't be stealing from the organization, because they had already paid for the stamp whether I returned the envelope or not--right? And I couldn't be stealing from the postal service, because they were still getting one stamp to deliver one letter--right? All I was doing was frugally putting to use a stamp that would otherwise be wasted--right?
Apparently the postal service didn't see it that way, because the envelope bounced. So, in a fit of pique, I grabbed all the remaining stamped envelopes I'd been saving in hopes that I'd be able to use them and just stuffed them into the mailbox. If they won't accept a perfectly good stamped envelope that's never been through the mail before, then they can go to the trouble of delivering a whole bunch of empty envelopes. That'll show 'em.
Actually, I have no idea what I meant to accomplish by this act of pointless protest, but it did make me feel better somehow.