My experience in locating people internationally is quite extensive.  I have located people on all continents except for Antarctica (too cold).  My most spectacular success was the location of a bag lady in Buenos Aires named Maria.  The woman had married a man from an influential Argentinian family.  She was uneducated and had been his nurse.  When the husband died nine years later, the family confiscated all of Maria’s inheritance, forcing her out onto the street.
However there was real estate in the US that had been forgotten, and had been escrowed by the State.  Since her husband was dead, Maria as the owner had to be located for it to be reclaimed.  When I found her, Maria was 68 years old, and had been living on the street for 15 years.  She lived in an apartment with no heat, no telephone, no electricity, and no water.  She picked up cardboad for a living at night.  And now she owned a valuable piece of land in the US.
Maria would never come to the phone to speak with me.  She was terrified.  I could understand her fear of her husband’s family.  They had probably intimidated her, threatened to kill her if she did not relinquish the rights to her inheritance. I could do nothing but turn over her contact information to the investment company that had hired me to find her.  I like to speak to every person I find to reassure them about who I am and to discuss why I have been searching for him.  But in this case, it was not possible.
I was never told by the investment company what happened to Maria’s property.  But I noticed that after speaking with her, my contact with the company was in an unusually good mood.  After thinking about this, I realized that I had innocently placed Maria’s life in danger.  If she sold the property for what it was worth, without means of depositing her money in a bank account, she would have been killed on the street for the cash.  If she kept the property, she could be killed by her husband’s family.  With her out of the way, the family would be the heirs to the valuable property.  Her only hope of survival would be to give the property away for just enough money for survival in the near future.
A year later, I received an email from a woman looking for Maria, probably for the same reason.  She had read a posting I had placed on a bulletin board, asking for information leading to Maria’s whereabouts.  I explained to the woman that any attempt to find her could lead to her murder, but she did not understand and begged me to give her Maria’s contact information.  I refused.