Markus Wolf — German Public Servant born on January 19, 1923,

Markus Johannes "Mischa" Wolf was head of the Main Directorate for Reconnaissance, the foreign intelligence division of East Germany's Ministry for State Security. He was the MfS's number two for 34 years, which spanned most of the Cold War. Many intelligence experts regard him as one of the greatest spymasters of all time... (wikipedia)

Making use of human weaknesses in intelligence work is a logical matter. It keeps coming up, and of course you try to look at all the aspects that interest you in a human being.
At our college we were taught a universal approach to find out about a person: what problems the person has, what difficulties, what personal tendencies and likings.
I tried to instill a different motivation, to give them the security and the conviction that they were doing something good, something necessary, something useful - if you want to use a grandiose expression, that they were doing something for peace.
There were some tragic cases of women whose love was abused, who for a certain time procured important documents or information, not knowing who for, what service they worked for, and for a variety reasons got jailed, were tried and sentenced.
You can't do anything if a person says no. In such a case, there's nothing you can do - unlike the popular cliche that pressure is exerted, or that maybe an unwilling source is done away with.