A computer hacker who disrupted access to the British Airways website for more than an hour costing the airline an estimated £100,000 was caught after he boasted about his crimes on Twitter, a court heard.
"Computer geek" Paul Dixon, 24, of The Avenue, Seaham, County Durham, also admitted hacking into police websites in October 2014 then bragging about it.
The unemployed defendant, described by his barrister as socially isolated at the time of the offences, smirked as he walked out of Newcastle Crown Court having been handed a suspended two-year jail sentence and ordered to pay £200 costs.
He admitted five counts of unauthorised modification of computer material at a previous hearing.
Dixon spent just a few dollars to attack the Police Scotland, Durham Police, webuy.com and British Airways websites, Sarah Wood, prosecuting, told the court.
He used Distributed Denial of Service (DDoS) attacks which swamp a target website with an overwhelming stream of requests for access, causing the site to work very slowly or to shut down completely.
Dixon paid for websites which are designed to stress-test sites against attack, the court heard, purchasing a time-limited DDoS attack.
The origin of such attacks is normally hard to trace, Recorder John Aitken was told.
But Dixon gave the game away by tweeting about his exploits.
Ms Wood said: "He could not resist boasting about his activities online on his Twitter account.
"Indeed, this appears to be the sole motivation behind his actions."
Dixon did not make any money from the premeditated hacks, the court heard.
He went on hackers' forums and appealed for friends to name targets for him.
His first attack, on the Police Scotland site, did not cause it to crash completely, but it did cause the number of legitimate users to fall considerably during the "outage" which lasted from 7.41pm to 9.01pm on October 16 2014.
The force said the public used the website to report hate crimes, adding that it was "crucial" to its public awareness role.
The following day Dixon mounted a less successful attack on Durham Police's site, and another on October 19.
He put webuy.com out of service for 15 minutes on October 21, costing the firm around £500 in sales.
The attack on British Airways happened on October 26 and lasted 68 minutes.
Ms Wood said: "While the website was not brought down, the traffic to the website was so great that legitimate customers would not have been able to access it either to make a booking or to check in."
The airline said that disruption to the website would have cost it approximately £100,000.
Durham Police investigated and traced Dixon after searching Twitter for messages about the attacks.
During his first interviews he claimed his computer had been hacked but changed his story, later boasting the police should employ him for his skills.
Sam Faulks, defending, said in one interview police recommended Dixon should take an interest in football, get outside and get some vitamin D from sunlight.
He said Dixon's world in 2014 revolved around Facebook, Twitter, group chat sites and computers.
"He was not living in the real world as we understand it, he was living in the cyber world," Mr Faulks said.
His client was back then "self-obsessed", "puerile" and "fairly isolated".
"He had delusions of grandeur, he was bordering on obsessed with getting fame for his actions," he said.
Mr Faulks said Dixon had kept out of trouble for almost three years since the hacks and prison for a "nerd" such as him would be tougher than for "tattooed, shaven-headed monsters" the court sometimes dealt with.
Recorder Aitken told Dixon his offending was "simply to boost your own ego".
He said he would take the "exceptional course" of not immediately jailing Dixon, but imposed a night-time curfew for three months and ordered him to be supervised for 12 months, as well as handing him the two-year jail term which is suspended for two years.