This is the problem with importing PUBLIC CONTENT YOU FIND ON THE INTERNET into a website. Not uploading from your computer, or importing from your own account somewhere on another site. If the website actually makes a copy of the media (picture, etc.) and stores it on their servers, they should hope that the DMCA still considers them a safe harbor.

I think their best bet is to store the images only as a cache, and not as a permanent import. If the site owner decides to take down the original, then the cache should disappear soon thereafter.