Funny you bring this up. This just came out today.

Cisco buys Netsift
By Peter Sayer, IDG News Service, 06/27/05

Cisco Monday said it has agreed to pay $30 million for a
year-old start-up, Netsift, which develops deep packet
processing technology. Netsift's system can be used for
detecting network attacks as they happen.

Netsift, a privately held company in San Diego, was founded last
June and employs 15 people.

The deal, worth $30 million in cash and stock options, remains
subject to regulatory approval and other closing conditions, but
should be complete by the end of July, Cisco said.

Read the full story at:
<http://www.networkworld.com/nlciscoalert2923>