Basically, I think that security cameras are nice. It helps police solving crimes, it reduces property and premeditated crimes and so on.
However, it gives a false sense of security in public places. If a country doesn’t have a sufficient safety standard, there is nothing that security cameras can do.
Futhermore, there is a seriously point, security cameras can be used to attack the privacy. George Orwell showed it in his book – the famous 1984.
In conclusion, I agree with the security cameras if it won't be used to limit our liberty.
OBS: "Security cameras" são objetos, logo o correto seria se referir a "elas" com o it.
Espero que tenha ajudado!