The network I use has never allowed the transfer of illegal files. The MP3 format, while not always, is most often used as a means of storing ripped music. I am not about to go into bat for the record industry, given that most elements of it are just capitalist swine but at the end of the day the law is the law and there is a precendent being set by many networks that they have a responsibility to make sure their networks are not being used for filetrading (of illegal files).
Naturally, the networks owned or sponsored by corporations are moving first simply because they have the means to cough up when sued.
