I read some people do that and that hence there are safeguards in place to prevent it, but what's the point? Suppose I know little about C++ and devise an ingenuous trick to game the system and gain reputation - at the end of the day the fact remains I still know little about C++, and people/interviewers would definitely ask how I got such a high reputation on Stack Overflow while I am so bad at programming! Seriously, wouldn't most of us feel uneasy if we get, say 10k reputation that we don't deserve? Who would love that?
So what is the reason people cheat to gain reputation on Stack Overflow? It's not like they can cash it in for hard cash! Do they think they can fool their recruiters with that? Or is it mostly newbies out to impress friends/girlfriends?