I have a lot of respect for cops. Whilst some may abuse their power and enjoy the "power trip," the majority do not...and besides, how is that different to any other profession? People abuse their positions in all manner of fields. I'm going to be a lawyer - most people go on about how lawyers are corrupt liars who can never be trusted. Never have any of lawyers I know been like that, or have the people around me ever come across anyone like that, although, no doubt a small minority do manipulate the system for the betterment of themselves and their clients.
And we do need police. Most of their work goes un-noticed or is not fully appreciated. If we did not have then, however, I'm sure we would appreciate the stability and safety they provide. I dare say the people who have criticised them, would not have the courage, strength, awareness or concern for society to undertake the phenomenal job that our police officers do.