Agents at GCHQ monitor ' large numbers of emails ' to detect terror threats . Spies use ' bulk interception ' powers to track down terrorists such as ISIS . Intelligence and Security Committee said UK spies were not breaking law . GCHQ was not ' collecting or reading everyone 's emails ' , committee said . But it is ' unavoidable that some innocent communications ' are snooped on . Spies at GCHQ , MI5 and MI6 have been sacked for ' inappropriate ' snooping . Spies have been sacked for misusing a vast computer system containing millions of pieces of personal data about British citizens . The committee found that MI5 , GCHQ and MI6 had all sacked – and in some cases sacked – operatives for unapproved access .
Agents at GCHQ monitor 'large numbers of items ' to uncover terror threats . Spies use 'bulk interception ' powers to track down terrorists such as ISIS . Intelligence and Security Committee said UK spies were not breaking law . GCHQ was not 'collecting or reading everyone 's emails ' , committee said . But it is 'unavoidable that some innocent communications ' are snooped on . Spies at GCHQ , MI5 and MI6 have been sacked for 'inappropriate ' snooping . Spies have been sacked for misusing a vast computer system containing millions of pieces of personal data about British citizens . The committee found that MI5 , GCHQ and MI6 had all disciplined – and in some cases sacked – operatives for unapproved access .