In a recent report, the Federal Judicial Center summarizes the findings of a follow-up survey of district court judges. The survey was designed to assess the frequency with which jurors used social media during trials and deliberations in the past two years and to identify effective and appropriate strategies for curbing this behavior. The survey also examined the frequency with which attorneys use social media to conduct research on potential jurors during voir dire. Although the detected use of social media by jurors is not common, it does occur and most often took the form of revealing confidential information about a case, according to the report.
See MEGHAN DUNN, FED. JUDICIAL CTR., JURORS' AND ATTORNEYS' USE OF SOCIAL MEDIA DURING VOIR DIRE, TRIALS, AND DELIBERATIONS: A REPORT TO THE JUDICIAL CONFERENCE COMMITTEE ON COURT ADMINISTRATION AND CASE MANAGEMENT (2014). Full text of the report and appendix with jury instructions available here.