A CNet article has a bit of the background.
From the Florida Supreme Court, new jury instructions to be adopted statewide:
During deliberations, jurors must communicate about the case only with one another and only when all jurors are present in the jury room. You are not to communicate with any person outside the jury about this case. Until you have reached a verdict, you must not talk about this case in person or through the telephone, writing, or electronic communication, such as a blog, Twitter, e-mail, text message, or any other means. Do not contact anyone to assist you during deliberations. These communications rules apply until I discharge you at the end of the case. If you become aware of any violation of these instructions or any other instruction I have given in this case, you must tell me by giving a note to the bailiff.
…
In this age of electronic communication, I want to stress again that just as you must not talk about this case face-to-face, you must not talk about this case by using an electronic device. You must not use phones, computers or other electronic devices to communicate. Do not send or accept any messages related to this case or your jury service. Do not discuss this case or ask for advice by any means at all, including posting information on an Internet website, chat room or blog.
You can read the whole thing here. (PDF download)
A sign of things to come? I can only image it is. I would expect almost every state to adopt similar rules sooner rather than later.