Wellll, maybe. While the lefties are experts at this sort of thing, I can't endorse it, although turnabout is fair play.
I am one of two guys who do a lot of election year yard-sign distribution here in Sarasota county, Florida. We also handle putting these near polling places on election day, as well as getting these signs put at every viable street corner and throughway that we can.
I can personally attest that, in these parts, ripping up GOP-candidate's yard signs by the score at 2 AM and leaving them in the dumpster is a democRAT specialty. In the last thirty days prior to the election, there's very few signs that stay in place more than a few days before they disappear. Sure keeps us busy.
There are countermeasures that can be taken to, er, "inconveinence" an such thievery, but I will not go into details here.
You could always affix the signs to tilt-rods, heh heh heh...
"I can personally attest that, in these parts, ripping up GOP-candidate's yard signs by the score at 2 AM and leaving them in the dumpster is a democRAT specialty."
You might consider spraying some kind of non-watersoluble dye on the signs that will come off when someone takes it, then can't be taken off easily. Something that would not be noticed at night, but only the next day when the perpetrators look at their hands. I don't know what this would be, but I'm sure someone else might have an idea.