People need to understand that words have meaning. Just because 'free speech' is protected by the constitution doesn't mean that you can (and should) say any crap, at any time, without thinking about the consequence.
When you say stuff like:
fuck a boston bombing wait till you see the shit I do, Imma be famous for rapping and beat every murder charge that comes across me.
Let's take a step back here, and assume for a minute that he REALLY was planning something - and not just talking tough. If he did it, and he posted this stuff on Facebook, and the FBI didn't do anything about it.....what would the fracas be then?
The FBI is incompetent....they knew he would do it, yet they did nothing, etc, etc, etc.
It's really a lose-lose for them. They can either take preventive measures, or do nothing in the name of 'free speech protection' and risk the chance that this latest bozo is actually going to follow up with action.
Kudos to the FBI for taking this seriously and showing people you can't just say crap like this without any consequence. Living in a free society comes with a cost. Not saying that a recent terrorist event was "nothing" is one of those costs.
It's simple really.
Also, if you think you aren't living in a free society, try moving to Saudi Arabia, many countries in Africa, Cuba, Bolivia, many S. American countries, many eastern european countries, etc.