I don't think anyone has mentioned this yet, so I might as well: unless they changed it after I left, JTV has been deleting videos older than a week for many years. I wrote the original (well, almost original) system, and IIRC, we took it down to a week of storage back in mid-2009 or so.

JTV caught quite a lot of static for "not giving more than a week's notice", but it's pretty hard to do that when you're going from one week of storage to no weeks of storage.

Also, since people are asking: back when I first worked on it (circa late 2008), we started by installing (again, IIRC) 40TB of RAID6 disk space, and that was enough to store about a month of video before we ran out. By the time I left, we had something like 4-5x that capacity, and we were down to a week of archive storage. So that should give you some perspective on the amount of data involved....and it's probably gone up substantially since then.