I'm not an expert on this but I believe that a silencer is considered restricted by the National Firearms Act of 1934. My opinion is that even with the ATF-issued permit to have it, it would not be a good idea to make it known that you have it. I assume that so few people have silencers legally that carrying a gun around visibly with one attached would likely cause an unwanted police encounter. Since these are regulated federally, the police may not be aware of the legalities behind it and you could end up downtown while they figure it out. It is possible that even if it is legal in accordance to federal law, it may be illegal according to state law. Just my opinion but I could be wrong.