They have a supect for the sasser.a worm.

HANNOVER, Germany (Reuters) - German police have arrested an 18-year-old man suspected of creating the "Sasser" computer worm, believed to be one of the Internet's most costly outbreaks of sabotage.

Previous versions of Netsky, for example, were programmed to attack the Web site for an education server in the German state of Lower Saxony where the German suspect lived, security officials points out.

If the Sasser author is part of the Netsky group, which calls itself the "Skynet ant-virus group" this could be the single biggest arrest yet in bringing down a virus-writing gang, officials said.

"The police may just have cracked the Netsky gang with this arrest. The whole ring may be broken wide open," said Graham Cluley, senior technology consultant at Sophos Plc, a British-based security outfit.
Now that would be interesting.