The ABA says that there are no ethical issues with scouring social media sites for information about potential jurors (or even jurors in deliberation. The opinion compares this information to any other publicly available information. LinkedIn is also declared free game, contrary to an earlier New York Bar Association.
Some attorneys have said they still won’t do Linked In searches, because it notifies the juror that their profile has been viewed by the attorney and it may make them feel uncomfortable about serving. Note that you still shouldn’t add the jurors as a friend and you shouldn’t follow them or “otherwise invade their private Internet areas.”