When a person travels to another country, the traveller has to go through immigration checks. The purpose is to ensure that undesirable people are not allowed into the country. Is this a good way to carry out the task? Is it producing any beneficial results?

This approach of immigration control seems to be adding a lot of inconvenience to ordinary people and is probably not achieving its purpose.

Here are the practical problems:

1. We know only of some undesirable people, but not the others
2. The undesirable people can travel on a false passport
3. There are other ways of entering a country illegally.
4. The undesirable people need to live somewhere, so they are allowed free movement in their own country anyway.

I wonder if there can be a re-think of the entire approach of immigration control?