It is a federal offense to interfere with political signs.
They remain the property of the candidate and here they have 7 days to pick them up after the election and I think there is a fine if they don't. Some candidates might reuse them another year.
However it is the same material as the popular boards so I would hate to see them dumped in the landfill!
I've never seen the ink rub off. They are professionally printed at least the ones I have seen.