Unfortunately the financial issues caused by the withholding of the payment may put some publishers in a position where they simply can't afford legal help. If it's just a person that had an article or app go viral unexpectedly, and they never receive a payment, they may well not have the money or years required to take on a multi-billion dollar corporation. They'll be upset, but they'll just move on. Facebook and Google know this, which is why they do it to people all the time [1].

[1] http://www.businessinsider.com/google-search-ad-policies-cos...