A teenager accused of bringing computers at America's biggest port to a standstill was part of a gang of hackers, a court has heard.
Mr Caffrey said he had hacked into friends' computers to test security
Aaron Caffrey, 19, is alleged to have set up the group called Allied Haxor Elite.
Mr Caffrey, who is accused of crashing systems at the port of Houston in Texas, admitted being part of the group but denied he had ever illegally hacked in to a computer.
The teenager, from Shaftesbury in Dorset, told Southwark Crown Court that hackers operated legally, but that people who entered computer systems illegally were known as "crackers".
Prosecutor Paul Addison asked Mr Caffrey, who suffers from a form of autism called Asperger's Syndrome, if he had seen the film Hackers.
Elite is the name given to the best of the group targetting the FBI in the film.
The teenager said he had seen the film a couple of times, but dismissed it as "eye candy" and denied there was any link to his group.
He said: "A hacker is someone who is good with computers and is usually a programmer.
"I have hacked into computers legally for friends to test their server security because they asked me to but never illegally."
Scheduling systems at Houston - the eighth largest port in the world - went down after they were bombarded with thousands of electronic messages in September 2001.
The attack put ships at risk by blocking crucial data for navigating in and out of the harbour.
Jurors have heard that investigators traced the source of the attack to a computer at Mr Caffrey's home.
The trial continues.