What are the main advantages and disadvantages of video surveillance in public space?

Question

Accepted Answer

Pros: better public safety, lower crime, catching criminals, collecting evidence, everyday convenience. Cons: misuse, threats to privacy, doubtful effectiveness, high costs.

Advantages
Example
Disadvantages
Example

Improve public safety
Monitoring natural hazards
Misuse
Blackmail

Lower crime rates
Surveillance of sales floors
Threat to privacy
Profiling

Catch criminals
Monitoring people at airports
Doubtful effectiveness
Cameras can signal that a target is worth attacking

Collect and provide evidence
Documenting hooliganism
High costs
Staff-intensive review of footage

Everyday convenience
Traffic monitoring to prevent jams

The utilitarian case rests on the left column. The deontological objection lives in the right column's privacy and misuse rows. And "doubtful effectiveness" challenges the utilitarian case on its own terms.
Go deeper:

Wikipedia: Closed-circuit television — includes research on how effective CCTV is against crime.

Advantages	Example	Disadvantages	Example
Improve public safety	Monitoring natural hazards	Misuse	Blackmail
Lower crime rates	Surveillance of sales floors	Threat to privacy	Profiling
Catch criminals	Monitoring people at airports	Doubtful effectiveness	Cameras can signal that a target is worth attacking
Collect and provide evidence	Documenting hooliganism	High costs	Staff-intensive review of footage
Everyday convenience	Traffic monitoring to prevent jams