Cheetah is a plagiarism bot run by @anyx. By default it doesn't actually flag material, just comments with where it was found elsewhere. Since it's not perfect, there are humans that are notified to followup on what it does have concerns about. Sometimes, it's just wrong (I've seen it refer back to older posts that while by the same author, aren't the same post) and other times it finds links to the same post that was 'cross posted' (posted in other places) by the true author.
If you see a cheetah comment and it's not correct you can leave a reply like, 'yep, that is a post on my non-steemit account' but you'll probably be asked to verify that it's your account. (There are various ways to go about this.) If the wasn't asked, anyone could steal and repost your content elsewhere on here and make money off that, which I'm sure you wouldn't want done with your creations.
When images aren't yours, just leave a source link so people can see where they came from. I saw one of your other posts where cheetah commented but you said it came from pinterest. That would be a handy spot to have left a source link to the pinterest page it came from.
Plagairism is a major thing that the entire Steemit community needs help monitoring by @cheetah and @steemcleaners. If you ever feel that there is an issue you can talk with some of these people in the Steemit Abuse Channel in steemit.chat.
There needs to be better options available and cheetah should be fixed before being released, and at the least renamed. I just made a post about this in a comment here with better links showing @anyx directly ignoring comments, at least myself, and later when he does reply to me, oh my it is not very civil, so it is making it harder to approach this person to see what can be done to make sure this bot is working fine.
https://steemit.com/adzcoin/@marketingmonk/adzcoin-adzbuzz-blocking-ads-and-bravely-earning-bitcoin-the-cryptoverse-172-warning-contains-emotionally-charged-rant#@cryplectibles/re-marketingmonk-re-seablue-re-marketingmonk-adzcoin-adzbuzz-blocking-ads-and-bravely-earning-bitcoin-the-cryptoverse-172-warning-contains-emotionally-charged-rant-20161225t114406884z
I do not believe anyone thinks the cheetah bot was built with bad intentions, just at the moment it is doing way more harm than good and my only suggestion to the maker or to anyone listening, just rename the bot so all the false positives that it does constantly hit, no longer bring shame to the users. Because once you get hit by the bot, it does in fact start flagging your posts and comments all over, it is really horrible for a user who does not use steemit chat or feel the need to defend their original art because it didn't live up to some robot's standards. Steemit is awesome because of actual people and users, having a bot ping things is not giving the right message.