[Wall Street Journal]

In response to attacks on researchers by animal-rights activists,
Congress in 2006 passed the Animal Enterprise Terrorism Act. The bill
made a critical change to the legislation it replaced: Demonstrators
could now earn a sentence in federal prison if the target of their
attention felt threatened, regardless of the protesters' actual
intention.

The law has emerged as a central example of how Congress has eroded
the legal concept of mens rea, which is Latin for "guilty mind"�a
long-held protection that says a defendant must know they've done
something wrong to be found guilty of it.

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full story:
http://online.wsj.com/article/ SB10001424053111903791504576586790205241376.html