Cheetah doesn’t care about whether you own the rights to the content. Cheetah is there to serve as a warning that the content may already have been used, published elsewhere and thus earned.

It’s actually rather good an approach in order to prevent that people earn x times from the same article,

Sadly enough it doesn’t work with certain professional authors/journalists who after a year (or more) publish unedited articles which have been published previously in magazines already. They get both the magazine’s check and then Steem brownie points. It shouldn’t matter they publish the unedited cut, they’ve already been paid for the article.