Yes, a number of countries with national ID systems have (wisely) designed the system such that there is no secrecy associated with the number, and people can a

Yes, a number of countries with national ID systems have (wisely) designed the system such that there is no secrecy associated with the number, and people can and do give it out freely without worrying that someone will use it to compromise their identity. Sweden's system works this way for instance, as does Estonia's. The United States can and should create a system similar to this, which would entirely end the problem of stolen Social Security Numbers once old-style SSNs were phased out in favor of the newer, better system.