This new ITV drama exposes just how many police officers lied and tricked members of the public into relationships with them, in order to spy on members of organisations campaigning on issues like animal rights and anti-racism.
Some of these police officers lived with their "targets" and had sexual relationships with them. There are even cases of them fathering children with the women they spied on undercover.
A long running inquiry is still investigating this scandal, but action needs to be taken NOW to close the gaping holes in our legal system so this kind of undercover operation never happens again.