Bitcoins aren't individual. You just have addresses with an associated sum, once two different addresses send 1 Bitcoin each to that address, those are equal and if you send 1 Bitcoin from the address who just received it, it's not one of Bitcoins that was received that got sent, it's just two values being updated at the same time (sender's amount decremented, receivers amount incremented).

What you can do, is blacklist specific addresses, and deny receiving/sending to anything that been "in contact" with that address. But you will for sure end up blocking more than you want with this approach, although that might not be a huge issue for the ones who are trying to block things.