Seems that cellular networks are susceptible to the same types of denial of service attacks that have plagued the Internet. A paper published by Penn State says pushing 165 SMS messages per second is sufficient to congest both voice and messaging traffic in all of Manhattan. While cellular companies say they have safeguards in place, researchers contend that "all major cellular networks were vulnerable" and a skilled hacker with a single computer, a list of a several thousand cellphone numbers from a common area, and broadband access could do the deed. Researchers even went so far as to prove (on a small scale) their theories by "very carefully" testing with their own cellphones. Believe them or not, it's only a matter of time until the theory is tested on a massive scale now that the detailed paper has been released online.