About me: I've been using WikiCommons since its inception in 2004. Eventually I nominated myself and became administrator. Back in the days of old all images who lacked source or license had to be individually nominated at Commons:Deletion requests. I nominated something like 1400 images before the rules changed and images could, under some conditions, be deleted at sight.
I still keep an eye on Commons:Deletion requests although I don't nominate a lot anymore.
I must have tagged thousands of images for missing some vital information. My modus operandi is simple: I tag, contact the author and check back again a few weeks later. In a few cases I delete at sight, album covers for example. So if you happen to own a record company you should probably try to present some undisputable evidence that you own the copyright or show that you are a credible WikiCommons user.
Generally, I trust uploaders to get things straight from the start. A few things I've learned is that:
- Photos of US politicians are possibly public domain
- Photos of NASA-related space photos are probably public domain
- Photos of paintings may be public domain but this depends on who the painter is
- Images sized 1600x1200 probably comes from a digital camera and may have been taken by the uploader
- Images sized 300x200 probably comes from a web page somewhere and were probably not taken by the uploader
- All alarm bells go off when I see Template:Copyrighted free use