What was the problem after all, "political protest", "destroying property" or the $700k charges made by "Anonymous" ?
Attacking civilian targets is wrong regardless of which side is doing it. Having previously engaged in the same behavior does not make the act any less wrong, or the vilification any less deserved.
What about a single civilian in a civilian building filled with a company of soldiers? In the law of armed conflict this kind of thing is called "perfidy" and brings no protection.