Criminal background checks should be mandatory for everyone going to reside in a foreign nation for some longer time.

For foreign teachers, business people, cionstructiion workers - simply everyone. For example, sex tourists abusing children come from all sexes and all walks of life. [edited]

Running a criminal check on anybody entering a foreign country to live and work (especially in a position of authority such as teaching) is normal and nothing to worry about if you have nothing to hide. It certainly shouldn't be viewed as a "bloody criminal background check" as if it's troublesome to you. If you have reason to view it as such, to me that's a good indication that you have something to hide.