In the UK, police officers have for years been recruiting people, including campaigners and activists to spy on their friends, comrades and even their own families.
Just how many in the country have been converted into informants is a closely-guarded secret within the police.
There are no published figures, but the current total is believed to run into the thousands.
The police have many subtle ways of recruiting informants.
They often use blackmail, for example, confronting a person they wish to recruit with some sort of embarrassing private or political secret that he or she is desperate to keep quiet.
Others may agree to become an informant in return, say, for the dropping of outstanding criminal charges.
Some (though it is rare) sign up out of a sense of public duty or service to the country.
Some are driven by feelings of jealousy towards other people or campaigners because they feel threatened or are jealous.
Some said they were worried that the particular group they belonged was not being run to their liking, according to a claim by the police.
Some were already criminals who offered their ‘services’ as a way to get rid of whom they they saw as rivals.
It has even been rumoured that some informers have masqueraded as abuse or crime victims, in order to gain payment by discrediting genuine claimants.
However, the most common inducement, appears to be cold hard cash.
They are not doing it for the money. Some people do…. That’s a motivating factor for people. That’s absolutely fine. My first question to them would be – is that a motivating factor for you, because I would need to know that
.The financial rewards enjoyed by individual informers are also a closely guarded secret by the police.
Sources have even suggested a ‘sliding scale’ that depends on the value of the information handed over.