This is pretty serious, especially to artists who create and sell adopts/charecters etc.

There has been a recent rise in theft of art, particularly adopts and charecters.
Recently people having being stealing adopts and other people's charecters (ocs) and selling them on, sometimes after altering, tracing or renaming them etc.

If you see suspicious activity you should report it!
I.e. You see a charecter you recognise being sold by someone.
It would also be a good a idea to contact the owner of said charecter aswell.

This is happening on DiviantArt in particular, but it has recently been spreading to here.

Take a look at this journal;
http://www.furaffinity.net/journal/4836460/