Yeah, that’s exactly my point: For me, the one time I’ve supplied home security camera footage to law enforcement, the officer who requested the video said I could deliver it on a CD or flash drive. I didn’t want to give up a flash drive, and the CD-Rs I already have, so they’re cheap and available, and I didn’t mind burning files to one of those and dropping it off at the local patrol station.
When managing other security cameras and DVRs was part of a previous job and we had a law enforcement request for footage, I’d usually crop to the relevant video for that and burn it to disc for them to take away, as well.
You mean you can’t just throw it up on YouTube? 
I concur with what others have said about just zipping the files into an archive and doing a single upload that way. They should have access to software that can stitch them together, if needed.