I'm really glad someone else has this problem. I used to think the laundry gnomes stole my favorite panties and put them in the same place as all of the unmatched socks, but now I know where they're really going. I occasionally catch men discreetly picking up my panties as they are getting dressed.
A sweet, innocent, "Oh, thank you for finding my panties! I was looking for those!" usually results in the panties back in my hand and an embarrassed look on the man's face.
Panty-thieving bastards must be trying to relive their glory days of frat house panty raids.
Then again, maybe some of them really are just trying to be helpful.
Guys, if you are trying to steal some panties, just ask. Pretty, lacy panties run anywhere from $4-$30 a pair, so a nice tip to cover the panties plus the time and effort to replace them is polite. And let the lady pick the pair she wants to give you. Some of her lingerie may have been given as a gift, or is irreplaceable limited-edition stuff. Have some consideration when you're stealing things.