I've downvoted all of his posts in this thread >:D

Back to being noob. :p

Who said it wasn't spray paint? For all you know, it could be raw sewage. =)

Well, it has worked, but only to some small extent: Ralackk now has 1341 rep, which means he must have solved a problem (and get to 1342), then lost a point to your negativity.
Anyway, I'd say having him let reach the fifth star is worth more than keeping him 1337.

There is no fifth star.

I don't suppose the GOG staff would be such scoudrels as to hint at something that doesn't even exist.

GOG hinted at some nice surprise for those who reach "maximum reputation", and also said reaching five stars is quite an achievement. For these, it is suspected something nice happens to those who reach five stars. Of course, "maximum reputation" can mean anything, even ten or more stars, but the text seems to imply five is the max.
Anyway, here's the text I was referring to.
"5. What is this “rep” thing on the forums?
Rep is the user's reputation rating, showing how respected and well-known you are in the community. You can quickly estimate a user's rep by looking at the number of stars next to their rep value. Getting one or two stars is fairly easy, while five stars is a serious achievement. Those who earn maximum reputation can expect some kind of nice bonus (surprise, surprise! :)."

Probably a pat on the back and a gift card or something.
Or System Shock 2.

Or an NPC name Ralackk in The Witcher 2.