Is it illegal to give someone else number to someone without permission?

think it SHOULD be illegal to put someone else's number on the internet without permission. my best friend did it to me, and i got a bunch of numbers from out of area destinations to my cell phone. And I've gotton threats..because she put it as her number on facebook..but it was really my number in her info..not hers. then i just turned my phon off and got another number.