A juror who contacted a defendant via Facebook, causing a £6m drugs trial to collapse, has been jailed for eight months for contempt of court.
Joanne Fraill had admitted the charge, in the first UK case of its kind.
London's High Court heard that Fraill, 40, of Blackley, Greater Manchester, had contacted Jamie Sewart, 34, who had already been cleared in the drugs case.
Solicitor General Edward Garnier QC said Fraill's case had been taken to court to protect jury integrity.
Sewart, of Bolton, was given a two-month sentence suspended for two years after she was found guilty of contempt.
Because other defendants were still on trial at the time of the contact between Fraill and Sewart, the judge decided to discharge the jury and the drugs case in Manchester, which cost £6m, collapsed.
Fraill cried uncontrollably in court, and gasped "eight months" - as did her family - as her sentence was handed down on Thursday.
The Lord Chief Justice, Lord Judge, who heard the case, then announced a short adjournment "for everyone to calm down".
Sentencing Fraill, Lord Judge said in a written ruling: "Her conduct in visiting the internet repeatedly was directly contrary to her oath as a juror, and her contact with the acquitted defendant, as well as her repeated searches on the internet, constituted flagrant breaches of the orders made by the judge for the proper conduct of the trial."
Later Sewart said: "I really feel for the woman [Fraill]. She's got kids. She apologised and she's not a bad lady."
BBC home affairs correspondent Danny Shaw says Fraill is likely to spend four months in jail, at which point she'll be eligible for early release.
Mr Garnier said any form of communication by jurors was subject to the same rules as those laid down in the court.
"One doesn't need to get too hung up about the magic of the internet," he said.
"Jurors have been able to gossip with their neighbours, be influenced by their friends and go to the public library to look up things. What is important is that the integrity of the jury system should be preserved and protected," he said outside court.
"Whether you communicate by Facebook, whether you research on the internet, whether you talk over your garden fence and are influenced by others, you must understand when you take an oath as a member of a jury, when you disobey that oath or when you disobey the instructions of the judge, and it is discovered, you may very well be held in contempt."
The case, brought by the Attorney General, Dominic Grieve QC, was heard by Lord Judge, sitting with Mr Justice Ouseley and Mr Justice Holroyde.
Lord Judge had previously told Sewart that any prison sentence on her would be suspended because she has a three-year-old child from whom she had already been separated during the crown court trial.
At the High Court hearing, mother-of-three Fraill admitted she had made online contact with Sewart and discussed the case with her while the jury's deliberations were continuing.
She also admitted revealing details of the jury's deliberations during that online conversation - contrary to the Contempt of Court Act 1981 - and conducting internet research into a defendant whose case she was trying as a juror during the trial.
That was despite the judge reminding all the jurors that they must decide the case solely on the evidence given in court.
Fraill was a juror in a case which had already been halted twice.
On 3 August last year, the judge in the third trial of the alleged drugs gang gave jurors the option of deciding the verdict by a majority rather than unanimously.
But the High Court was told the trial was stopped the following day when Sewart's solicitor informed the court that his client and Fraill had been in contact via Facebook.
The court heard the initial contact came after Fraill went on the social networking website and tracked down Sewart, saying: "You should know me - I've cried with you enough."
Fraill was said by her lawyer to have felt "considerable empathy" for Sewart as the trial "gathered in momentum and intensity".
The two continued to talk about the case and used expressions such as "lol" and other internet slang.
Peter Wright QC, for Fraill, said his client was terrified at the prospect of prison and was distraught and inconsolable about what she had done.