It is common to post a neutral topic and then give our own vote in its favor.
On the other hand we can post another neutral topic and never vote for it.
Abuses and self centrism could come into play but how much damage can 1 single vote cause? None.
Now, I've seen users loging in as someone else to give credit to themselves as another person ( not at Woltlab, lol).
Those are the real "bad"ones, lol!