I'm about to email you to this effect, but it's clear you have grounds to file a counter-notification per 4shared's policy (see http://www.4shared.com/dmca.jsp)
There's nothing I hate more than copyright trolls, and while I'm not featured on the commentary tracks, as a Dunshelm Player I would urge you to go ahead. Hopefully 4squared follows their policy and sides with us.
In the worst case scenario, the files would need to be hosted elsewhere. There's free services like Tindeck and Soundcloud, or proper web hosting - I used to use Feralhost, for example.
