Share copyrighted stimulus material with collaborator We've been showing a number of copyrighted movies in a psychology experiment. I would like to share the movies with a collaborator at the other side of the world, who wants to run an alternative analysis. As our behavioural data is event timing-related and as we've shown the movie in separate clips with some additional overlays it would be best if we just shared the stimulus files directly. We've got a lot of videos with relatively large (GB) individual size. 

What are my options? I've got no experience with file sharing, so am not sure what can go wrong here. I don't want to get into legal trouble for uploading them somewhere.
Non-profit research is one of the typical "fair use" exceptions to copyright law, so if it's OK for you to be using them for research, it's probably OK for you to share them with your collaborator as well.  

Every country has its own particular regulations around copyright, so it's definitely worth confirming with them. If you're just using short excerpts as user stimulus and not publicly distributing, though, that should be pretty well protected in most jurisdictions.

That bit about "not publicly distributing", however, is quite important. As such, if you want to share with your collaborator, make sure you do it with some sort of access-controlled sharing system like Google Drive, DropBox, BitBucket, or even your own FTP server rather than just posting it openly on a webpage somewhere.