Plumbers, hairdressers, street-sweepers - anyone can be a target of capture, torture and even murder.
Millionaire ransoms are demanded - but with kidnappers accepting sums as low as US$500, it means no-one is safe.
This story about one kidnap contains strong language and upsetting scenes.
Victims' names have been changed.
By staying inside they are available to give advice at all times. But it also means they can avoid being spotted by the kidnappers, who may be monitoring the property.
They will also be on hand to help the family deal with phone calls, to try to keep them thinking positively, and also, crucially, to help negotiate the ransom.
“This is a crime about greed, and it usually finishes with some money being paid,” says Morales.
...It's very unusual to have the opportunity to challenge a kidnapper on why he makes victims and relatives go through so much suffering.
Does he (the kidnapper) ever think about this? Has he ever felt any remorse?
Kidnapping is drastic, and quite cruel, but I don't feel any remorse at all. Sorry, I just don't.”
Crack (the kidnapper) is an example of how the booming business of the drug cartels in Mexico has spilled over into other crimes, such as kidnappings or extortions, sometimes to replenish their cash reserves.
Read more from the BBC [here].