Don't fall prey to these methods of VoIP abuse was an interesting article I found that could potentially help newcomers to VoIP protect themselves from being singled out of the pack.
"Voice over IP (VoIP) technology provides many advantages to companies and individuals over both traditional telephone services and traditional IP communications. But, like other technologies, it also brings with it the potential for abuse. And as more people implement VoIP, we can also expect more frequent exploitation of this potential."