Is this really what the police are for?

Over in the UK, the police have been rocked by spying scandals, with revelations that they spied on peaceful protesters, their critics, and pretty much everyone other than actual criminals. You'd think after that they would have learned, but apparently not - they've just been caught trying to recruit an informant to spy on students at Cambridge University:

Police sought to launch a secret operation to spy on the political activities of students at Cambridge University, a covertly recorded film reveals.

An officer monitoring political campaigners attempted to persuade an activist in his 20s to become an informant and feed him information about students and other protesters in return for money.

But instead the activist wore a hidden camera to record a meeting with the officer and expose the surveillance of undergraduates and others at the 800-year-old institution.

The officer, who is part of a covert unit, is filmed saying the police need informants like him to collect information about student protests as it is "impossible" to infiltrate their own officers into the university.

Is this really what the police are for? Spying on students so they're kept up to date about their protests? I don't think so. The police should focus on criminals - and protest is not a crime.