I think this depends what AD you are in, I have heard some stories turn nasty! Wearig a rep Breitling or Omega into an AD would probably not ring any bells, unless closely inspected, but wearing a Patek or Audemars rep into the relevant AD would be like showing up to a Ferrari dealership in a bodykitted Toyota Mr2, claiming it was real!!
It is an illegal hobby, and whilst they may have no powers of confiscation, it is the effects in the wider sense that would have more repercussions for us -such as advertising the fact that communities such as ours exist.