Copyscape is an online tool for discovering spammy duplicate content potentially scraped from other websites, and the websites copy-pasting your original content. Despite of the noble goal to reduce search engine spam, the service is actually encouraging its users offering them spammy html code for their websites to Defend your Site with a Banner. They have conveniently forgot to add the necessary
to the following banner code they are offering to everyone
Let's hope they get their spam issue fixed before someone report's them.