Scofflaw

Someone who treats the law with contempt, especially a law that is difficult to enforce. Originally coined during Prohibition in the United States - the OED, which designates the word "Chiefly US", traces it back to 1924:

Boston Herald 16 Jan. 1/2 Delcevare King of Quincy last night announced that ‘scofflaw’ is the winning word in the contest for the $200 he offered for a word, to characterize the ‘lawless drinker’ of illegally made or illegally obtained liquor. ‘Scofflaw’ was chosen from more than 25,000 words, submitted from all the states and from several foreign countries.

With the difficulty of enforcing copyright on the Internet, and the contempt (sometimes, perhaps, justified) with which some people treat others' rights online, it has acquired a new depth of meaning.