What I'm trying to say is, the majority of people don't include sources for their pictures, so it's hardly seen as an important problem on steemit. Misinforming people, by posting facts without sources is where the issue is, in my eyes. If you have time to check the plagiarism tag, there have been some great discussions going on that raise allot of good points.
RE: 5 Reasons Why EVERYONE Should Name Sources On Steemit (Preventing Plagiarism And Mis-information).