I logged into my account today to find the red box notifying me that the account was canceled, couldn't be reactivated, and to contact them if I have questions about the account. Also, I can't make any edits 'while' it is canceled. That infers there could be an end to the cancellation.
It is a small account, between $100 and $300/mo. To my knowledge, I've done nothing wrong. I've had payments rejected before, but the account is current, has been for some time, and hadn't been altered for several months. During those months, the only active campaign was for one hotel property. The landing page has 2 adsense blocks, some affiliate links, unique editorial content, unique images and links to the other unique property pages.
It's not terribly important, it is a tiny % of traffic to the site. Adwords wasn't something I had found to be particularly profitable in my situation, and there are other alternatives. But is perplexing, and somewhat insulting.