What conservation laws do black holes respect? Not many. Mass-energy, angular momentum and electric charge are the only properties of what falls in that remain properties of the black hole itself. That means that all other ``conserved'' properties of matter, like baryon number, are `` mutable'' in the final analysis.
One consequence is that protons might experience gravitational
decay in which they collapse into a very tiny black hole,
only to immediately explode into (probably) a positron and some gamma rays.
The estimated lifetime of protons against such a fate is 
years, which is not too worrisome.
Other consequences are more interesting, but only philosophically: the interior of a black hole [with which we can never communicate] may have entirely different properties - or even different ``Laws of Physics'' - than what we drop into it. Wheeler has taken this idea much further than I can follow, but it does make for interesting thinking. Good luck.