According to their terms, Google can cancel any account at any time without having to offer an explanation. They also have a history of not replying to publisher problems at all. The whole 'Official' Adsense forum is run by volunteers and it's near impossible to speak to a real person. Even if they are hacked and thousands of accounts are cancelled I don't think Google will respond. I would so, so love to see a big p…
Aren't people like Appnexus and Openx alternatives? What am I missing?
Neither does what Adsense does per se. What Adsense does is it reads the content of the page, and loads relevant ads from from its database of ads (things people put in adwords) and from GDN (also things people put in AdWords, and DBM, only they're pictures). The GDN bit has always been a bit icky IMO.
So, no, they aren't alternatives. Chiticka and others WERE alternatives, but there was a quality control issue (also supply side issues, because Google is a HUGE brand) which led to their eventual demise and/or pivots to waaaay dodgier practices like popunders.