I've got a note under that identical IP that says "makes page thumbnails". Don't know if it came from someone here or something in raw logs. Was over a year ago, so raw logs aren't immediately accessible. Processed logs say they first picked up the front page, and later got the front page with all images.
Either for that reason or something else, I too have a block on 85.25. Cumulative effect, probably.
Yes, often there is, but I try when I can identify it to block around the user IPs because my user content driven sites (forums) depend on them. Often my most prolific posters are what we commonly call "post whores", who post all day long from their job. Their posts tend to drive many responses... hence I let them through.
Only legit users I block are those coming in through anonymous proxies because the same proxies also tend to bring comment spammers.