I am periodically asked why I mark images I upload as {{keep local}}. The answer is that there is no visibility o Wikipedia of what is happening to images on Commons. Below is a reply I have previously given (copyedited for civility).
- I do this as standard. I have had some bad experiences with images being moved to Commons, Commons finds a problem with it, does not inform the project from whence it was transferred, does not inform the author (who is on another project), does not inform the article which is using the image, and then Commons deletes the image. This is all entirely invisible to an editor on Wikipedia, it does not even trigger a watchlist of the article when the image is removed. If you are really on the ball, you might spot that the image has gone redlink next time you look at the article (but why should you look at an article you have already written?) but most likely you won't even see that because a bot comes around afterwards and removes all trace that it has ever been there. Commons does not always have a good reason for these deletions; sometimes it is just that the transfer was done incompetently and information is missing. Sometimes there just does not seem to be a valid reason: I recently rescued this image which Roger uploaded in 2007 which was deleted on Commons citing copyright violation. We know this was created by Roger and is properly licenced, so how Commons concluded copyvio is beyond me. Luckily, the user is still around to confirm he is the author, this is not always the case, on the Lecher lines article I was forced to recreate the image from scratch - completely wasted effort. We only spotted that the image from Miller effect had disappeared because someone noticed the text was referring to a figure that was not in the article. I don't want to have to keep checking up on what is happening on Commons, but even if I did it would not do any good since transferred images do not get put on my watchlist there.
And here is an example of a bot replacing Wikipedia images with improperly attributed Commons versions. Sagas like this one where images change without warning in a technical article to something that makes nonsense of the article and Commons have then to be fought to put it back also discourage me from using this system.
