You misunderstood, he's calling the cops thugs, not the protestors. If you read the rest of his website you will see that he refers to police as "thugs" regularly:
> US citizens: call on Obama to curb militarization of thugs.
> Everyone, call on Pasco to fire and prosecute the killer thugs
> "Flood Wall Street" protesters have been acquitted of charges; the thugs' order for them to disperse was ruled unconstitutional.
> It is good that they were acquitted, but there must be some penalty for thugs that violate protesters' rights.
And that is one reason why he is so terrible at communication. Nobody understands what he really means in that particular case, unless you were able to derive his specific meaning of "thug" from his previous writings. Inventing your own private sociolect and using it in published texts is a bad idea.
UK note: I had to check the reference to work out that the thugs mentioned had uniforms.
I found the playful use of 'used' along with other vocabulary changes to be reasonable and engaging. This playfulness with language may create problems for readers whose first language is not English.
> US citizens: call on Obama to curb militarization of thugs.
> Everyone, call on Pasco to fire and prosecute the killer thugs
> "Flood Wall Street" protesters have been acquitted of charges; the thugs' order for them to disperse was ruled unconstitutional.
> It is good that they were acquitted, but there must be some penalty for thugs that violate protesters' rights.
and so on.