Yes. It can also trick you into thinking a reactionary opinion is actually a popular one. For example in my country, ireland, there's been a few incidents were people of different nationalities have done unsavoury things caught on camera. This usually results of the comment section of the ireland sub to have a debate about whether there's too many immigrants in the country. Whichever side gets more upvotes is widely perceived to have "won" and bystanders will in turn adopt that position.
I don't think I've ever changed an opinion of mine to go along with the hive mind but the karma system has definitely discouraged me from commenting things because I would been downvoted into oblivion. It's not worth getting into arguments when you can clearly see people not siding with you.
