Hiya Gunnar
I like you am completely opposed to sharing someone else's commercial work on the net through a web site - it's doing that person out of a legitimate living....
However the copyright requirements are obviously complicated because Midi-spot themselves hide many of their song specific rhythms behind innocuous titles and maybe that's where the problem lies.
A generic rhythm with an innocuous title picked up on the web which can be converted to use for a particular song may be deemed to be nothing more than a standard built-in keyboard rhythm from some machine or other and therefore fair game for sharing...