Er... why?
Folks abused a spam button. What do you sue on?
That's like saying people can sue Kos for a troll's posted comment.
...about a matter on which we don't have all the info, for certain...
Was there a violation of the blogger's 1st Amendment rights? Perhaps. Then again, if they don't own the blog, then the folks that own the servers on which the blog's hosted may do whatever they wish...pretty much, anyhow.
Was there a violation of the blogger's 1st Amendment rights?
No.
You have First Amendment rights only against the government. I think it's fairly safe to assume that that doesn't apply here. I wonder if there are tort theories for which you could go after someone in this type of situation, but then there might not be any damages, if it's not a revenue-generating blog.
I don't think there is much of a legal case here. But I can tell you from experience pressuring large companies over political email that you do have leverage. Companies like Google ("don't be evil") are very responsive to the threat of bad press. "Google is censoring political speech!" is a real bad press story and may get them to improve their spam-flagging system.
Cost of public relations/damage versus legal fees versus a quick $50,000 for signing off on a confidentiality agreement...basic tradeoff...seen it done many, many times...for a lot more money in some cases, too.
Yes...obeying an order to STFU has its price... <grin>
Some people actually make a living for agreeing not to do certain things...LOL!
