It would be incredibly easy to add simple rules that restrict the ability to post photos and links.
Rules such as you can't post photos or links if you:
Signed up less than a month ago.
Have less than x number of posts.
Have had a post removed for breach of certain rules within the last month.
Have had a post reported but not reviewed and released within the last 24 hours.
Have posted more than two photos in the last hour.
This wouldn't remove the risk entirely but would make it more difficult for people who have bad intentions. It would also stop further images/links from being posted once an issue is identified.
It is also clear that there MUST always be someone available who can delete posts, ban posters, and see reports in real time.