Just weeks ago, GSM encryption was cracked, but everyone was all like, "No big deal, GSM is old." Now the encryption protecting 128-bit UMTS 3G has been cracked as well.
It's not a practical hack yet, with real time monitoring of 3G calls and data fairly impossible since it takes a computer about 2 hours to decode the encryption. But researchers have admitted that their technique is far from optimized, meaning the process can only get faster.
I dunno about you, but security breaches like this are precisely why I only have phone sex in person. [Cryptology ePrint via ars technica via phoneArena via gsmArena]