Are there formal or informal hiring bans in some academic settings based on gender and/or nationality? In early March 2015, an eMail by a female German professor apparently rejecting a male Indian applicant due to the 'rape problem' in India made news. (The issue is a bit more complex. There is some discussion whether the eMails were selectively quoted and the professor has since apologized.)

What bugs me however is the following paragraph (which may or may not be what the professor has written, and which seems to be ignored by the news media):


  "Many female professors in Germany decided to no longer accept male
  Indian students for these reasons, and currently other European female
  association are joining."


Is this a thing in Academia? Has anyone heard about hiring bans, either formal or informal ones, based on sex/gender and/or nationality?
You are unlikely to get examples about formal hiring bans, in particular in western societies. It would not only be frowned upon, as in this case; it would also be against university policies, if not downright illegal. The only formal hiring bans I could think of are those implied by more general rules. The most obvious case coming to mind is that about 20 countries don't allow people with Israeli passport to enter, which means they cannot study or teach there either (about half a dozen or so countries extend this to people with other passports but evidence of a travel to Israel). 

Unfortunately, it is possible that the professor was speaking a truth about what some consider in their hiring decisions...where usually they would only have the common sense to not explicitly admit the true reasons for their decisions. They would start where this professor is now: claiming that their labs are full. This is human nature, and academics are no better or worse than their fellow humans dealing with their fear and prejudice in regrettable ways.