A free society is a relative term. Free from tyranny, free from government oppression. Free from gov't interference. Those are all relative to those things happening (or happened) elsewhere. Regardless, I hear you on his rights being violated.
Let's assume for a minute that this was a credible threat and the FBI didn't follow up on it like this. Let's say he did do another bombing and killed 20 people, who would you blame?
It wasn't, which renders the whole rest of your point moot.
The kind of bad logic you're espousing is exactly what gets us zero tolerance laws, that in which any means are acceptable, no matter how absurd, if what it's preventing is bad enough.
It's outsourcing of judgement, something which has shades of grey, to a law, which has only black and white. This is not EVER a good idea.
How far are you willing to go stop a school shooting? Trample all over the first AND second amendments? Put the TSA at the front entrance of every school?
I find it very.... odd, that someone who can grok the nuance that "freedom" is a relative term is unable to understand that same nuance applies to other things as well.
From 2010, a story about a child who took a tiny toy gun (part of a lego figure) to school. The principal was going to suspend him, but checked with an official from the local education department.
(http://www.silive.com/news/index.ssf/2010/02/big_brouhaha_ov...)
...
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."
I agree that living in a free society comes with a cost, but it's pretty clear that this man's right to free speech is being violated. Also, the fact that there are countries with horrible human rights violations doesn't have anything to do with whether or not the USA is truly a "free society."