The head of MI5, the U.K.’s venerable domestic intelligence agency, has apologized for the years the organization excluded gay people.Until 1991, MI5 would not hire anyone known to be gay, and closeted employees who were found out would be fired, all because of a policy that considered gay people a security risk.“It must have caused all sorts of hurt to people,” MI5 leader Andrew Parker told the BBC in an interview upon his retirement. “And that has to be a matter of regret and shame for all