Why You Should Source;
When posting another persons Photo, Video, Words, ect, you are taking their possession. You didn’t think of that, you didn’t work to create that, you didn’t, you didn’t, you didn’t. If you take it and claim it as your own you are stealing from them. By not putting an acknowledgement or way back to them, you are saying that you are the owner. That is stealing.
Then of course I get the argument about “Deserving credit for finding it and posting it” or “How would I find people who posted it here” ect. I want to make this very clear. I did NOT say that you can’t add a way back to you. All I am saying is you MUST put a way back to the owner. By all means add a way back to your self as well. As long as you acknowledge that it belongs to this other person it’s all good.
This also leads to the problem of people reposting things they find on tumblr, with or with out sources is irrelevant. By the same logic that you have to source the photographer/owner, you also need to source who you got it from. Which is exactly why there is a *Reblog* option that does all the work for you. Stop trying to get followers by undercutting others.
Another issue that tends to come up is, “Why would I source Google” “Why would I source WeHeartIt, it isn’t the owner anyways” ect ect ect. To put it simply: Stealing from a thief is still stealing, unless you give it back to the rightful owner. I would highly recommend you use creditable sources to find pictures/videos/ect to post. For photos one of the best ones is Flickr, which is what I personally use the most. There is also 500px, and many others. They are many sites you can find creditable photographs on, and they have tons of photos. There really isn’t any good excuse not to use them.
Rebloging unsourced photos is just as bad as posting them. You are simply giving the thief credit and more chance of profiting off the theft. Be it advertisements on their blog, or simply gaining followers.