I do not know if it is illegal - he links to files which are open available on the internet. What he does is surely impolite, but hardly illegal. Deep Linking is only illegal if he links to password protected or otherwise private files. Move the files, he will get the message soon.

A ship in port is safe; but that is not what ships are built for.
Sail out to sea and do new things.
-"Amazing Grace" Hopper

Avatar image of me done by Chidori.