I access that info by using my eyeballs. Nothing more or less precise. Guesstimation.
I see less spam posts in UNIX/Linux than I do Windows during my time here. Whether that is the actual case, since I very likely don't see every spam post done 24/7/365.
I just removed a spam post in the General C++ Programming forum.
EDIT: 16 minutes later I removed another one from the same forum.
George P wrote:
All I know is when I see the <new> flag on the main forum list I go look and stomp on the bots as needed.
Personally I don't go to the http://cplusplus.com/forum/ page very often. Instead I mostly jump between the Beginners and the General C++ Programming forums. Of course I check the other forums too from time to time (except the Jobs forum) but much less frequently.
The reason I did it was so that people could see it was not only in the Windows forum and perhaps be able to draw some conclusions about the spam bots' choice of forum. But it's pretty meaningless so I guess I should stop.
I was cogitating on why the spammers appear to prefer spamming the Windows forum....do they think Win users are dumb enough (as opposed to *nix users) to click their toxic sewage links?