Secret government security vetting of job applicants

Governments may require security vetting in certain sectors and without informing the job applicant. People may be denied a job or promotion on the basis of information which they have had no opportunity to verify.
In the UK it is reported that one million positions are subject to secret government vetting of applicants, namely 1 in 22 of the working population. Security vetting occurs in both public and civil services, private sector defence contractors, telecommunications and the armed services.
(E) Emanations of other problems