It's pretty shitty of hosts who know there are rules against Airbnb to Airbnb their homes out, even shittier of the management of such buildings to lock or kick people out (would they do the same to friends and family they didn't recognize?), and shittiest of Airbnb to not take responsibility and at least put up these people elsewhere and stop allowing listings in banned buildings. Of course, if you're a multi billion dollar company, laws don't really apply. After all what are the consequences to Airbnb? None.