I think admin is pretty gosh-darn clear about this.
/forum/thread.php?id=316
"Especially beware of the members who post fakes from the internet instead of their own pics. A person who uses fakes is dishonest by default and thus unreliable and unpredictable by default."
/faq.html
"Legally you can post only the pics you have legal rights for. Generally those are pics of yourself you made personally or pics of other persons you made personally and have their implicit permission to publish the photos.
It's not exactly legal and is not permitted to post pics taken from internet on this site as in 99.99% cases you do not have authorization of the producer of those pics to publish them.
However, the site administration cannot know all the millions pics in internet and in most cases cannot tell if the pics are your own or taken from the net. Which means that only in case when someone report stolen/internet pics to the administration or in case when administration accidentally notice stolen/internet pics the account that posted them gets deleted.
If you notice someone posting internet pics, you can always report this. There is a "report abuse" button below every pic and a "report member" button on every member page.
Also, the administration cannot just take your word on it without any proof. Indeed if the member has obviously internet pics from different sources, proper actions will be taken. But in other cases the administration require some kind of proof - links to the pages with original images for example."
with emphasis on "Indeed if the member has obviously internet pics from different sources, proper actions will be taken."