I stumbled across a thief a month ago. This one was claiming photographs that weren't hers.
They faved one of my drawings, and when I checked out her DA page, something about what she wrote in her description of her work struck to being similar to what I've seen other thieves write.
I checked the work on tineye.com and got so many returns that it made it hard to determine if this was a thief,or just a popular photographer. I contacted another DA member who has a lot of experience of tracking down the sources of the stolen work, and quickly found two of the pieces belonged to other DA members. We both reported the stolen work and waited for action to be taken.
After three weeks I was still waiting.
Even though the two DA victims hadn't posted anything for quite a while, I noticed one of them was still logging in here. So I sent her a note pointing out the thief that stole their work. The next day she got the note and confronted the thief, and then posted the theft in her journal. Several of her friends showed up and left the thief a message.
To my surprise a couple hours later the thief was banned from DA for life.

So the question is this: What prompted DA to suddenly take action? The other person who reported the incident thought is was because she wrote a description of the theft, but I don't think that was it. I've written, (as well as other people I know) descriptions about thieves trying to sell prints of other Deviants work, but yet they weren't banned, and in one case we located the source of all but one piece of a thief's gallery, and that thief was never banned.

I think one thing that may prompt an investigation being taken are a lot of page views in a short amount of time, and not necessarily angry comments being left for the thief. I know of other people who had their work stolen and reported it, and after several days no action was taken.
As for being banned, maybe it was because some of the photos were from stock image companies.
Anyone have any theories?