That's hardly all the ALF does. Here's a partial list:

http://www.splcenter.org/get-informed/intelligence-report/br...

And, despite what you say down-thread, the FBI also considers abortion clinic violence to be acts of domestic terrorism. For example, scan this list from the FBI:

http://www.fbi.gov/stats-services/publications/terrorism-200...

From the same document:

  Terrorism is defined in the Code of Federal Regulations as 
  “the unlawful use of force and violence against persons or 
  property to intimidate or coerce a government, the civilian 
  population, or any segment thereof, in furtherance of political 
  or social objectives” (28 C.F.R. Section 0.85).

So, by that standard, firebombing feed trucks would be terrorism. Secret filming would not.