The policy for unlicensed/non-free content on the English Wikipedia requires that any non-free image on Wikipedia only be used in articles. Accordingly, Non-free images which are not used in the main namespace are deleted.
To give people a chance to recover images which were accidentally removed from articles we do not just speedy delete these images. Instead we tag them as orphaned images, and if they are still unused in the main namespace (articles) and still tagged, we delete them.
Because the orphan tagging doesn't require any complex judgment it was accomplished with an automated User:Gmaxwell's bot roomba and User:Betacommand's BetacommandBot used to perform this task but it is now performed by User:Hazard-SJ's Hazard-Bot.
This activity is not new, not controversial, and is the strong and long standing consensus on the project. Arguing against it is likely to only cause needless irritation.
But X isn't orphaned!
Please look at the filelinks section at the bottom of the image page. Sometimes there are multiple copies of a single image, and an image you believe is in use really is not in use.
If the image is only used in a userpage, portal, talk page, or other pages outside of the main namespace, it is considered orphaned for the purposes of our policy. Please see the text above.
If the image actually is used in a Wikipedia article then you may remove the orphan tag. This can happen because the image was temporarily out of an article due to vandalism or edit warring.
But my image is under a free license!
If the image in question has been released under a free license by the copyright holder then the image should not have any templates on it indicating a unlicensed/non-free status. Please correct the tagging. Please be sure that an image is actually released under a free license or is old enough to have had its copyright lapse before removing fair use tags.
The bot keeps retagging my image!
If the bot is retagging the image it is because the image is not used in the main namespace. As stated above, use in the main article namespace is a mandatory requirement for any non-free images on Wikipedia and use outside of that namespace is forbidden.
If, after reading the above, you believe the tagging bot is making an error please leave a message on Wikipedia talk:Non-free content/orphans. Do not edit war against the bot. The bot will not change its behavior if you yell at it, and if you are in error and repeatedly remove the tagging against policy you may be blocked.