From Bruce Schneier’s security blog:

Turns out that you can jam cellphones with SMS messages. Text messages are transmitted on the same channel that is used to set up voice calls, so if you flood the network with one then the other can’t happen. The researchers believe that sending 165 text messages a second is enough to disrupt all the cellphones in Manhattan.

Naturally, a stupid network would not suffer from such a performance bottleneck that can be exploited maliciously.

And IMS will keep you totally safe, 100% available, honest ;) No intelligent bottlenecks in this network! Move along please…

via Telepocalpyse