Off the top of my head - should be abround 2007😃
We only send out information about a takedown notice to the person who has the content removed.
There is 100% abuse in the system; in the last week we've received a couple of takedowns from fake attorney's (companies using DMCA to get a backlink) - there was a big piece on it on Hacker News the other day. But we aren't in a position to challenge any of this. We could disclose takedown notices, but it wouldn't probably change anything about how we respond to them.
There is no set minimum image quality. The image needs to appear clear at full size. It's a bit of a subjective criteria, but any jpgs submitted should be at 100% quality (we'll lower quality for thumbnails for fast loading automatically). Even that does not guarentee that an image makes in on Wallpaer Abyss. We focus on 'showcase quality': https://communities.alphacoders.com/topics/view/6853