I found this interesting post about the antisocial#018 – L’atelier d’héphaďstos compilation at the Yahoo! Music Groups website:

The official one is a harmless experimental music compilation. The dark side : each artist has included a reverse message in his track (which as we all know has a subliminal effect and therefore could influence behaviour and thought without the listener being aware of it). Remember that this technique was often used in the old heavy metal records. Offering this compilation allows you to manipulate someone.

Read the whole information, with detailed descriptions of included reverse messages here.