In State v. Dellinger, No. 3573 (W.Va. Supr. Ct. June 3, 2010), the West Virginia Supreme Court reversed a felony conviction of a Braxton County Deputy Sheriff due to a juror's "complete lack of candor" during voir dire. The juror and the defendant were MySpace "friends," but hardly knew each other. Still, the Court found that the juror should have disclosed the relationship, and also some other tenuous relationships she had with two witnesses in the case.
The Court also noted that, during the trial, the juror had posted on her MySpace page that she had "just returned from court" and was headed back there in the morning, noting that her mood was "blah." Although this incident of blogging during trial was rather benign, in footnote 11, the Court suggested that trial courts issue instructions to help deter jurors from using technology and social media for improper purposes during trial.
It recommended a model jury instruction endorsed by the Committee on Court Administration and Case Management of the Judicial Conference of the United States that tells jurors not to research the case, or blog about it, among other things.
It's clear that voir dire and jury instructions need to catch up with technology.