If you are suspicious that someone who you know is giving information to police....

There are a number of sure things and spy and policeman are not to be confused, therefore,....

A state agent i.e. an agent of military intelligence will interview you in your own home or if you have multiple residencies or he thinks that you have multiple tenancies on otherwise houses,he will call to your door but not come in because he works in association with those who come to people's house or houses to kill them. All he needs to know is where you live......

And as regards that other type of spy,one of the sort of person who knows the power of the media,he will visit a journalist in person to arrange either his death or the death of a member of his or her family...

Why?

That is his job,not policing crime, arresting criminals,preventing theft but the quelling of dissent and stopping the poor taking part in riots.....

ASK an undercover detective or suspect on a Sunday ONLY, "Have you signed the Official Secrets Act?" Do not say,simply," Is this the latest bunch of lyin' you've taken into?"

 Never say,"Why are you visiting me in my own house since you never invite me into your house unless it's for an unlawful purpose or purposes and to have me arrested?" 

 If you act properly,you can learn more from him than he can learn from you since paid spies are given to frequent bouts of conscience as are detectives.

Always remember,readers, the police recruit their officers solely from the children of businessmen, shopkeepers ,tradesmen and farmers and their informers solely from the social scum of the earth and families of the victims of crime and violence.

Those civilians of you who alert the police to drugs in your area or crimes of violence must learn that they will soon break off contact or hinder you in some way if you tell them to behave legally and to use appropriate force when arresting someone.

 The Irish police ignore most judicial  criticism. They are accustomed to random acts of violence committed by their colleagues and themselves.

 In my experience of Northern Ireland,if you tell these aforementioned police not to enter your house when you are absent,they will immediately arrest you and charge you with a criminal offence or detain you unlawfully, usually these days in a psychiatric hospital.

The home caller? Active measures?

 Act in good time as circumstances permit to protect yourself and your family from harassment by telling idiots,undercover police and drug addicts to leave.

Tell the aforementioned people,"I don't want to listen to any shit from you or your street-runners or the scumbags you mix with to pick up information in my own home. Your entire existence marks you out as a pariah and an outcast,and rightly so."

....

In situations of great danger....

Tell another person or more than one person about a suspicious individual, where you are going and who you are meeting.

.....

While it is not a universal guide you will find that a real spy-I am talking about someone who accepts money from police for information -sticks out like a sore thumb. Contrary to literary confusion and cinematic image,he is usually a thug and a hooligan.

You will know that he spies on others by the fact that he follows his foil around and tries to catch him in a three-cornered tie with police. This is not a universal rule since friends and acquaintances may dog you if they are hard up for chat and companionship but it is a general rule of thumb.