VoIP spam is an as-yet non-existent problem which has nonetheless received a great deal of attention from marketers and the trade press. Some pundits have taken to referring to it as SPIT (for "Spam over Internet Telephony").
Voice over IP systems, like
e-mail and other Internet applications, are susceptible to abuse by malicious parties who initiate unsolicited and unwanted communications.
Telemarketers,
prank callers, and other telephone system abusers are likely to target VoIP systems increasingly, particularly if VoIP tends to supplant conventional telephony.
See more at Wikipedia.org...