Nicholas Jacobsen
American hacker who spent the better part of a year inside T-Mobile's customer database — including a Secret Service agent's email.
Jacobsen was in his early twenties when he found a hole in one of T-Mobile USA's web applications that exposed records for hundreds of subscribers: names, Social Security numbers and passwords. The intrusion ran through much of 2004 and came to light only after he offered data for sale on a forum.
What made it embarrassing was who was in the database: a Secret Service agent who handled work email on his T-Mobile phone. Jacobsen could therefore read internal documents from the very agency investigating him. He pleaded guilty in 2005 to unauthorised access under the CFAA. That same year Cameron Lacroix emptied Paris Hilton's T-Mobile phone — the carrier was having a rough time.