Yes, there are.
Granted, OC will deter some criminals from an attack, but if it doesn't, congratulations: you have just made yourself more of a target. If an armed robbery does take place, in a store or a bank or whatever, who do you think the bad guys are going to take out first?
Then there is the PR angle. For some reason, OC makes a lot of people very uncomfortable, especially at first, and a lot of people will see OC as akin to exhibitionistic, paranoid, wanting to call attention to their having a gun, etc. (I believe it was Badge Bunny who used the term 'Billy Bad-Ass'. That was cute, BTW.)
That makes sense. Thanks for your thoughts