It would be nice if we could block certain individuals from our family trees just as we can block them from sending us messages. Some people are repeat offenders at copying things from trees and haphazardly adding them to people in their tree with incorrect names and other info. It's an affront to those who DO take accuracy seriously. (or as accurate as humanly possible)
Maybe that is part of blocking them in the email, but I could not find anything in the help section that this is the case.