This is possibly the most ridiculous thing I've ever heard of among jurors. There have been reports of jurors' own judgement being undermined because they've been looking at Twitter while court cases are ongoing, and because that'd make it easy for campaigners or lobbyists to get messages across to them and influence their decisions. The Sun (hideous conflict-provoking vultures that they are, but nevertheless) reported that a judge had to restart a trial after a juror accessed her Facebook, put up details of the court case and started gathering her friends' opinions on whether the defendant was guilty. This is, as we all know, fucking retarded, and only a conscious effort not to make snap judgements prevents me from instantly visualising this juror as a drink-raddled fake-tanned chav (basically white trash for any Yanqui folks who don't know the term) along the lines of this venomous harridan, whomever the fuck she may be.
There have also been reports of jurors investigating rape cases using the Internet. Because that's fucking unbiased, isn't it.
The report mentions that they're considering classing use of these resources for purposes related to the court as being in contempt, which sounds reasonable to me. There's only so many ongoing court cases you can Google before you realise that maybe the fringe sites calling for the lynching of the defendants aren't legitimate evidence.