Apple Macs and random file extensions

[maniac]

Students using iMovie (I think that's what they're using) on our networked macs seem to be filling up their home folders with large amounts of big files with seemingly random extensions, see attached picture.

 

Are these some sort of temporary file and can they be deleted does anyone know? I'm pretty sure they are as they are hidden, but as I'm unsure how this program works I don't just want to do this incase it's some vital working files or something.

 

Any help appreciated,

 

Regards,

 

Mike.