Now, I don't take kindly to spammers, so I checked his account here on Arduino.SE, and.. it's complicated.
Every post but two has a link to his personal website, often without further comment and almost never even hinting that he wrote them. He also doesn't mention the answers, but forces people to click through. So far, so bad.
What's problematic is that the information in the link may very well be good answers to the questions, sometimes the only answer. I'm not sure what to make of this. I don't want to flag all the posts as spam. Maybe a stern warning from a moderator is in order?
I know too little about the culture here at Arduino.SE, but I feel that something is not right with those posts.