Google will suspend AdWords accounts include (but are not limited to) the following:
- data collection sites that offer free items and the like in order to collect private information
- arbitrage sites without relevant and original content that are designed for the purpose of showing ads
- affiliate sites without relevant and original content that are designed to drive traffic to another site with a different domain
- "get-rich quick" sites
- malware sites that install software on a visitor's computer
- poor comparison shopping or travel sites whose primary purpose is to send users to other shopping or travel comparison sites, rather than to provide useful content or additional search functionality
These are guidelines, but they will ban more as Adwords deem non- beneficial to the public. If someone writes into Adwords and a manual reviewer reviews your site, deciding it is indeed non compliant, or if enough complaints can be found on "rip off" complaints sites, then the account and all related accounts, domains will get banned too.
The AdWords system visits and evaluates advertiser landing pages on a regular basis to ensure this compliance.
When suspending accounts, Adwords determines whether an AdWords account is "related" based on various factors including subscriber data, account content, and other information.
If you're a six figure ex adwords advertiser and want to get back into the Adwords game, with new accounts and all, contact me here for "Google Slap" support.