The US government maintains a “No Fly List” and airlines are required to check passengers against it before allowing them to fly. They maintain other lists that trigger increased security screening and potentially harassment.
The lists are pre-crime profiling. Not even based on science. And it’s also done very very poorly. People get on the list by mistake, because they’re related to someone who is on it (or just have a similar name), or because they visited the wrong country in the wrong year. .