Seen it a few times, most commonly from Discogs. I was looking recently at a band-specific site though, and wondering if I should ask them if they’d object, but noticed some files had already been uploaded…
No policy, basically. If the image is watermarked, indicate it.
I’ve wondered for a while if we should have a Code of Conduct for uploading cover art.
For example, a certain site we all know has a rule against reposting any of their images on other sites, so by extension their images would be forbidden from being uploaded to the CAA. Additionally, I’d avoid adding images if they contain watermarks from pirate sites.
Unless they actually hold copyright over the images in question any such rule can only ever apply to members of their site. (Also, I have no idea what site you’re talking about – and I’d prefer if you didn’t tell me too.)
This is a bit more of a grey area, but I’m leaning towards uploading them anyway, if they’re the only source for a given Release available.