Well, someone stole my yard signs today

[Warpy]

30. Tablespoon of cayenne pepper

or a whole habanero pepper, water, few drops of dish soap in a blender. Paint the edges of the sign with the resulting mixture. I guarantee you he will reconsider his Christian soldier vandalism career the next time he takes a leak.

Even if he's wearing gloves, he is likely to touch the fingers and palms of them when he removes them.

This isn't usually kids, by the way. When cops have busted any of these guys, it's been because the back of the pickup truck is full and the load hasn't been tied down or covered by a tarp, triggering a traffic stop. The sign thieves who have gotten writeups in the paper (and there are only a few of those) have been white, male, married, and over 40.

The hot pepper won't do any physical damage, at all. It will just feel very nasty if he rubs his eyes, picks his nose, or takes a leak.