This is not news. Suing someone into submission is an old tactic. Almost anyone with well-funded enemies can expect to be battered by a series of legal actions designed to defame, harass and intimidate. He11, it could even happen to the President of the United States!
When companies do it to consumer groups and individuals, it's called SLAPP (Strategic Lawsuits Against Public Participation). See:
http://www.freedomforum.org/speech/1998/2/17slappsuits.asp
Governments use this tactic too, as firearms manufacturers know. The cities filing suits blaming gun makers for crime don't need to win in court if they can drive Glock or Ruger out of business with court costs.
The difference in the news article cited is that the defendants actually did something wrong to the plaintiffs. The Aryan Nation wasn't just speaking their mind here, they attacked a woman and her sons. The "guards" were acting in their role as members of the Aryan Nation, and the legal principle called
respondeat superior says that an organization is liable for the actions of those who act on its behalf. (DISCLAIMER: I am not a lawyer and this is not legal advice.)
The right to seek legal redress is precious, as is the right to free speech. We need both. Sometimes, we have to find a balance between rights, and this is where we have to put our trust in 12 of our fellow citizens.