I talked about the pointless use of downvotes. You will understand if you read the post completely. And I have not violated copyright law. I have used either my own photo or a licensed photo. I have a photo in this post named "No Talk" that is my own photo. Licensed photo means copyright-free photo.
Even if I don't source it, it doesn't violate copyright law.

However, it is advisable to include the source in the licensed photo as well.

I have never been downvoted on steemit. Because it wasn't spam in Steemit's rules.
You can test if you want. If You share a copyrighted photo in a post without the source. hivewatchers will catch you. If you share licensed photos in another post without the source. hivewatcher won't tell you anything. This also applies to your own photos.

However, it is advisable to include source to the licensed and your own photos.