I had doubted that they were true Quicktime videos though. Since Quicktime itself cannot play those .mov files that are spammed, but players like VLC or MPlayer can. I guessed it was a windows video format that simply used the same file extension.

The QuickTime .mov format is a containor format. The actual format inside could be anything. Similar concept to AVI.

Ignoring .mov files less than 150 MB is very wise though.