spam variants may include exploits related to location-aware devices (e.g., advertisements tied explicitly to the user’s location) and spam and spam-like payloads other than text delivered to mobile devices such as cellular telephones. An example of the latter is that with the increasingly popular use of voice-over-IP, junk phone calls (also known as SPIT, for spam over Internet telephony) may come to be a problem in the future. Research will be needed to address these new forms of spam as well.