Telecom equipment maker NEC Corp. has its eyes on Spam over Internet Telephony (SPIT), a theoretical problem that combines open VoIP systems and the proliferation of unsolicited email. Known as VoIP SEAL, NEC’s solution detects and blocks SPIT by observing the way calls act – a method based on the Turing test, devised in 1950 by the father of computer science Alan Turing to tell if a caller is human or a machine. According to an NEC test, VoIP SEAL detected and blocked 99% of the SPIT thrown at it. Although potentially annoying, SPIT is not a substantial threat today (see Telemanagement 238, September 1, 2006: "The Truth About SPIT").