Re: protesting with obscene signs

There is a difference between disturbing and obscene. Very little is considered obscene, and the photos you describe generally wouldn't even come close. Context matters, also, and images that are used in order to argue over important social and political issues are entitled to very strong protection under the First Amendment. Even without this context, though, I very much doubt any lawmakers would try to bar the use of disturbing medical images in public. I doubt even more that such a ban would survive a legal challenge in the courts.