My question to you is: how are you assessing the costs? Do you know how many crimes have been stopped as a result of these cams? Do you know the extent to which our privacy is being lost and our data is being used against us or others?
I take into account publicly available information (news articles), factor in personal anecdotes, and reason about human nature and incentives. I know the extent of reported abuses, and I do my best to extrapolate. It's not perfect, but such is life.
To be clear, even if we all agreed on the data, I still would not expect everyone to take the same position. There are subjective differences in values.
Flock has put out a report claiming 10% crime in the US is solved using their technology. There are of course counter argument, that claim this is not valid.