MP3 Music Downloads...

Is it legal to download from MP3 music sites like IpodKid.com, MP3Items.com or Mooza - MP3 Search Engine?

Itunes.com charges money for music and these sites give them away for free.

So this is my question.  Can I get into trouble for downloading music for free?

I recently created a Mp3 music playlist on eSpew.com and posted it into my MySpace profile.  Can I get into trouble or sued for that?

Additional Question - If I use a web surf proxy when visiting music sites, does this protect me?

Mods - I apologize if I posted this in the wrong section.  Feel free to move the post to wherever you feel is best.