This is the most common complaint from users about listings. Fake photos are not fair to the visitors and other advertisers. Your photos may be marked as fake because of a user report - you will receive a warning mail when this happens. If you do not agree with the decision you can apply for verification. It is free and you can verify here.

What is not OK?
If you are an advertiser and do not follow the rules, your account and any current account associated with you and and future account will be blocked.
Underage photos or photos of children in any listing.
Trafficking, enslavement or anything similar.
Abuse, violience or oppression towards colleagues.
Online trolling or other defamation towards other users.