Person with amnesia interacts with the person who did the bad thing that caused the amnesia and has no idea they are still in danger.
Someone is spotted across the street, is gone after a truck goes by.
Nobody ever sets their phone to silent or vibrate to avoid getting caught receiving calls they should not be receiving, or to avoid having their hiding place compromised.
Web sites for even the smallest of newspapers have a completely searchable archive with results that often look like microfiche.
