The United States has similar laws, where licensed Private Investigators have to at least supervise investigations (it's a bit like having a licensed pharmacist

The United States has similar laws, where licensed Private Investigators have to at least supervise investigations (it's a bit like having a licensed pharmacist on duty while less-trained people actually hand out the meds, or having a medical doctor supervise the work of a group of physician's assistants). There are some exceptions, but most of the time you need a license to go snooping around. These PI licenses are also a major perk of law enforcement careers, as it's sometimes difficult to get the required work experience without time in law enforcement (unless you don't mind working for nearly-nothing under a PI taking photos of insurance & workers compensation cheats, unfaithful spouses, etc. for years). That background check company was almost certainly operating within the bounds of the law. They were just doing it Really Poorly.