Counterfiet comic art.

Despite feeling a little flattered when finding a forgery of a peice of my artwork it really won't do. My image of the page is not good but the fake looks nicely drawn with some fine pen work. The signature at the bottom looks like mine as does the penciled page identification next to it, so well done forger. I have tried to contact the web page where the forgery is featured. An attractive page someone might well want to buy it but an original Ranson it is not. 
On the same website there was another pice mislabeled as mine but that was just a mis-attribution. Careless rather than criminal.
I wouldn't know but is this kind of thing common? Are any measures and checks in place to prevent it? We should be told.