Flickr problems

Well, I have temporarily taken down my Flickr Jigsaw Puzzlemaker. I had one of thousands of users complain to Flickr that their images were accessible via my site. Uhh, isn't that what the Flickr API is suppose to do? I checked and that user's images are also available on all the other Flickr apps as well.

To make a long story short, Flickr asked me to take down my site until I obtained a commerical API key. No big deal, I was fine with that. However, then they said I would also have to authenticate users to Flickr before they could use my jigsaw application! There in lies the problem. None, I repeat none of the other apps require you to log into your flick account before you can search for images. I'm waiting for a response to see if this is some new requirement. If it is, it stinks and will pretty much kill my app.