Occasionally, yeah. Sometimes people have weird text formatting, like narrower margins because they press the return key before typing all the way to the end of the text box. So if they go anon I know exactly who they are. I'm just observant like that.
There are people who frequently go anon, so I wouldn't know their usernames. However, I can usually tell which questions are being asked by the same anon person just based on the topic, and the content of the question.
My age gives me away usually, although I know there are a few others in my bracket. I usually won't say anything anonymous that I won't say under my own user name, though.
As for others, I notice a common theme about the anonymous questions and while I may not recognize who it is, I recognize them as having asked the question or some variation of it previously. I start nice on the first question, but if they repeatedly ask it I start becoming a bit less so...: P
The only time I can tell is if the person has the same exact question all the time. Although usually those people always post anonymously. So I don't know who the user is, but I can tell it's the same person.
Yeah, just one person on here. He usually bitches about women, ugly people, and "nice guys". "Isn't it funny how women bleh bleh bleh" "Don't you agree that most women blah blah blah" Forgot your user, but you know who you are.