The problem is that you might not get to walk away scot-free from this even when you want to.
One thing I can gaurantee will help you: make no attempt whatsoever to profit from this. Don't put up any ads. Don't have any affiliate links. Profiting from a (potential) crime or infringement makes it 100x more dangerous.
Thankfully France is not the only french-speaking country.
Don't be surprised: I'm taking this "fuck it, we need to do something" approach. We've been trying to get heard by content owners for years but nothing has worked. If this is the only thing we can do, I'll do it.
I'm more curious than anything to see if this will get me into any real legal trouble. I believe what we do is legal, I also wish we didn't need to do it at all.
As mentioned previously, if I could have simply built a good front-end that calls an API to license content, I'd have very happily done it.
Coming from the music industry, when I hear the excuse "but it's hard to create a worldwide licensing system like you ask", I say bullshit. Both the movie and music industry are waaaaaaaaay behind in terms of technology, and everything is so inefficient.
Ever tried to obtain the rights to (legally) burn a CD compilation of your favorite songs? You'll have to send snail mail, make phone calls, wait weeks for confirmation (while you pay, of course), if you're very lucky you'll be done in 6 months with a lot of work. This is not the way it should happen.
Some start-ups (say, http://official.fm/) are working towards resolving the situation on the music side: providing a friendly licensing platforms for content owners is a good start. But that only works for small to middle content creators/owners. The big will never bow to that, they'll always go for their own, often crappier, solution.
So, I'm willing to work on their own terms: you give me an API key, a doc, and you decide the pricing. That's all I ask. Then we can all get busy building apps around content, which is what is dear to my heart.
Respect. You should totally allow people to download your databases (including those wallpaperesque backgrounds for each movie). Probably as a torrent. :)
In the meantime, it's still a great product building experience for us, even if we make $0 out of it.