Facebook comments and statuses are classic examples of hearsay evidence, but they generally may fall under one of several hearsay exceptions (notably, statements of party-opponents in probate litigation).
It is interesting to see the way in that Facebook evidence is being sifted by the country's appellate courts. Though not a Georgia probate law case, the case of State v. Eleck is one in which the appellate court agreed to exclude Facebook conversations as evidence, despite that they were crucial to the state's case. As part of its reasoning, the Connecticut Court of Appeals cited the "general lack of security of the medium," the implication being that someone else could have broken into the alleged declarant's Facebook account and posted the messages.
Chicago evidence law Professor Colin Miller disagrees with the appellate court's reasoning in an excellent blog post here. My sympathies are with Mr. Miller. In an age where the majority of a person's communications in a day may actually be by electronic means, it should be left to a jury to decide the likelihood that a particular communication was the result of alleged "hacking" into the declarant's account.
At Tanner Pittman, LLC, we combine adroit knowledge of trial skills and evidence law with expertise in estate planning and probate to bring value to our clients in will and estate contests.
UPDATE: The only Georgia case that seems to deal heavily with the use of Facebook evidence is the criminal stalking case of Placanica v. State. That case, however, does not set forth any new law regarding the admissibility of such evidence.