ATLANTA, December 8 (Reuters Legal) - The explosion of blogging, tweeting and other online diversions has reached into U.S. jury boxes, in many cases raising serious questions about juror impartiality and the ability of judges to control their courtrooms. A Reuters Legal analysis found that jurors' forays on the Internet have resulted in dozens of mistrials, appeals and overturned verdicts in the last two years alone.

For decades, courts have instructed jurors not to seek information about cases outside of evidence introduced at trial, and jurors are routinely warned not to communicate about a case with anyone before a verdict is reached. But jurors these days can, with a few clicks, look up definitions of legal terms on Wikipedia, view crime scenes via Google Earth, or update their blogs and Facebook pages with snide remarks about the proceedings.

The consequences can be significant. A Florida appellate court in September overturned the manslaughter conviction of a man charged with killing his neighbor, citing the jury foreman's use of an iPhone to look up the definition of prudent in an online dictionary. In June, the West Virginia Supreme Court of Appeals granted a new trial to a sheriff's deputy convicted of corruption, after finding that a juror had contacted the defendant through MySpace. Also in September, the Nevada Supreme Court granted a new trial to a defendant convicted of sexually assaulting a minor, because the jury foreman had searched online for information about the types of physical injuries suffered by young sexual assault victims.

Reuters Legal, using data from the Westlaw online research service, a Thomson Reuters business, compiled a tally of reported decisions in which judges granted a new trial, denied a request for a new trial, or overturned a verdict, in whole or in part, because of juror actions related to the Internet. The data show that since 1999, at least 90 verdicts have been the subject of challenges because of alleged Internet-related juror misconduct. More than half of the cases occurred in the last two years. Judges granted new trials or overturned verdicts in 28 criminal and civil cases -- 21 since January 2009. In three-quarters of the cases in which judges declined to declare mistrials, they nevertheless found Internet-related misconduct on the part of jurors. These figures do not include the many incidents that escape judicial notice.

'GUILTY! HE'S GUILTY!'

Over a three-week period in November and December, Reuters Legal monitored Twitter, reading tweets that were returned when jury duty was typed into the site's search engine. Tweets from people describing themselves as prospective or sitting jurors popped up at the astounding rate of one nearly every three minutes. Many appeared to be simple complaints about being called for jury duty in the first place, or about the boredom of sitting through a trial. But a significant number included blunt statements about defendants' guilt or innocence. Looking forward to a not guilty verdict regardless of evidence, one recent message stated. Read another: Jury duty is a blow. I've already made up my mind. He's guilty. LOL.

Last month, a person using the Twitter name @JohnnyCho wrote that he was in a pool of potential jurors in Los Angeles Superior Court, and tweeted, Guilty! He's guilty! I can tell! In later tweets, @JohnnyCho said he was picked for the jury and that the defendant was convicted. Traced through his Twitter profile, Johnny Cho, director of communications at a Los Angeles entertainment lighting company, acknowledged he was the author of the tweets but declined to discuss the case. Reuters Legal forwarded the series of tweets to Superior Court spokeswoman Patricia Kelly for comment. She called the tweets definitely a problem, and said the court would look into the matter. Ten days later, the court's acting public information director, Mary Hearn, said the court had concluded that because Cho sent his Guilty! tweet before he was chosen for the jury -- and did so from the jury assembly room, not from inside the courtroom -- it was acceptable. She declined to identify the case.

In another recent case, Susan Dennis, a Seattle blogger, posted in late October that she was a prospective juror in the Superior Court of King County, Washington. The prosecutor during jury selection, she wrote, was Mr. Cheap Suit and annoying, while the defense attorney just exudes friendly. I want to go to lunch with him. And he's cute. She also wrote that the judge had instructed jurors not to tweet about the robbery case but had made no mention of blogging. Reached by email, Dennis responded that she had no comment. Reuters Legal described the circumstances to a jury consultant, who independently notified the court about the blog. That day, the judge dismissed Dennis from the jury pool for ignoring his instruction not to communicate online about the case, according to Amy Montgomery, one of the prosecutors. We believe, probably stupidly, that jurors follow judges' instructions, said public defender Jonathan Newcomb. They don't.

Complications caused by Internet-surfing jurors have arisen in major corporate disputes. In September, Exxon Mobil Corp challenged a verdict awarding $104 million to New York City in a ground-water contamination case, in part because two jurors allegedly looked up information online. U.S. District Court Judge Shira Scheindlin denied a new trial, but she acknowledged in her ruling that search engines have indeed created significant new dangers for the judicial system.

COURTS FIGHT BACK

Courts are trying to figure out how to keep jurors unplugged. Some judges now confiscate all phones and computers from jurors when they enter the courtroom. California last year updated its civil jury instructions to bar jurors from all forms of electronic communication. Florida courts added a stricter instruction, stating that jurors using the Internet must not disclose your thoughts about your jury service or ask for advice on how to decide a case. At least six other states have taken similar steps. In January, the Judicial Conference of the U.S., which oversees administration of the federal court system, recommended that federal judges use instructions stating that jurors cannot search the Internet, websites, blogs, or use any other electronic tools.

But with so many people accustomed to their always-online lifestyle, it may simply be unrealistic to think they'll leave that impulse behind at the courthouse door. In pre-Internet days, jurors might have gone home and talked about trials, but who knew? Now they publish their views online, leaving an electronic trail that increasingly is providing grist for lawyers to challenge verdicts. Some experts now argue that rather than try to stifle jurors from pursuing information on the Web, courts need to figure out how to help them do so in a responsible way. Georgia State University Law School professor Caren Myers Morrison says it's frustrating for jurors when information presented at trial is confusing, especially when they know they can easily access more data online. We need to rethink the jury's role for the 21st century and restore some of the jury's active engagement in the process of fact-finding, she said.

That challenge is complicated by an apparent generation gap between older court officials and the Internet-centric culture where many younger people reside. Last December, during the corruption trial of former Baltimore Mayor Sheila Dixon-who eventually agreed to resign from office after a plea deal -- Maryland Circuit Court Judge Dennis Sweeney, age 65, learned that five jurors had become Facebook friends. Sweeney called a hearing on the matter. After that, he said, a young male juror posted on his Facebook page, F--- the Judge. Judge Sweeney said he asked the juror about the offensive comment and was told: Hey Judge, that's just Facebook stuff.

(Research assistance by Mary Kivimaki and Leah Hauge of Westlaw; Editing by Eric Effron and Amy Stevens)