Sounds like the government caused this boycott by trying to rein in the exact activity that the boycotts are protesting. If they're censoring it, it's probably because they're trying to soften the effect on overextended banks. If the government hadn't insisted on functioning in the first place, the mortgage holders would still be in ignorant bliss.

If China could afford to damage these banks (or if the people who run them fail to have the right connections and attitude), it seems like it would actually benefit the government to publicize these boycotts as further support for the crackdown.

In the US, we'd just call the papers and get them to all run stories about a new trend among right-wing conspiracy theorists to stop paying their mortgages, relate them somehow to tax protesters and sovereign citizens, call them freeloaders, and insist that the figures being spread around about the number of people involved are probably from covert Russian sources.

edit: I mean, after that we'd start censoring, demonetizing, think-tank fact-checking and downranking, but only after accusing everyone involved of being a terrorist.