Applying to a private detective is often the only way to resolve a delicate or controversial situation. Police officers work with obvious facts and act according to the charter, limiting the capabilities and powers of investigators.
How much attention do we pay to personal security? It seems that it is enough to equip the house with a security system, set an alarm in the office and a GPS on cars. Still buy a watch with a tracker for children, and voila – everybody under the protection and control.
In order to remain completely invisible in the 21st century, you would need to live far away from civilization, where there is no mobile communication, internet, POS terminals or all the regular modes of communication to which we are accustomed.
We live in an environment where the “peaceful atom” is invisibly present – naturally occurring radiation. Homes and offices are often sources of radiation. A family can live for decades in an apartment and not know that the old sensor or the remains of a slate roof are nearby “working properly”.