No, in the simplest terms. Their methods may not be the best way to "police" their vampire world, but what they do is only to protect their anonymity. They see that humans would seek to destroy their world and them if they were discovered, and they cannot allow that. What is done, is done to protect all; the nomads, the cullens, the denalis, and of course the volturi.
They are the rulers and they enforce the law. They are not just shitty little vamps but true kings. They have a purpose to do what they do. vampires wouldn't survive without laws, they would be noticed par humans and with their new machines - killed. The Volturi are good, not very good ou the best, but still good rulers.They have this job even though it's the reason why others may not like them.Somebody has to make the rules - they did good ones. So they're not just some aléatoire creepy vampires :)