Are mp3skull, soundowl, and video2mp3 safe?

Because I just blew $1,500 on this macbook pro in the first place. Apple will be just fine without $1.29 for every song they need. And besides, the musicians I listen to don't make much money off itunes anyways, they pull in money from concerts. I'm paying $40,000 a year for college and don't need to give up a buck and a half every time I want to listen to music.

And does that apply to all three sites I listed?