ible ▁release ▁of ▁class ified ▁information ▁about ▁these ▁programs ▁will ▁have ▁a ▁long - term ▁det r iment al ▁impact ▁on ▁the ▁intelligence ▁community ' s ▁ability ▁to ▁detect ▁future ▁attacks ." ▁ ▁In ▁August , ▁Chair man ▁of ▁the ▁J oint ▁Chief s ▁of ▁Staff ▁Martin ▁D emp sey ▁said ▁that ▁Snow den ▁" has ▁caused ▁us ▁some ▁considerable ▁damage ▁to ▁our ▁intelligence ▁architecture . ▁Our ▁advers aries ▁are ▁changing ▁the ▁way ▁that ▁they ▁communicate ." ▁ ▁In ▁October , ▁former ▁G CH Q ▁director ▁Sir ▁David ▁Om and , ▁speaking ▁of ▁how ▁useful ▁for ▁Russia ' s ▁intelligence ▁services ▁Snow den ' s ▁stay ▁in ▁Russia ▁could ▁be , ▁told ▁the ▁BBC : ▁" Part ▁of ▁me ▁says ▁that ▁not ▁even ▁the ▁K GB ▁in ▁its ▁he yd ay ▁of ▁Phil by , ▁Burg ess ▁and ▁Mac lean ▁in ▁the ▁ 1 9 5 0 s ▁could ▁have ▁dream t ▁of ▁acqu iring ▁ 5 8 , 0 0 0 ▁highly ▁class ified ▁intelligence ▁documents ." ▁Snow den ▁stated ▁that ▁he ▁had ▁not ▁le aked ▁any ▁documents ▁to ▁Russia . ▁ ▁Also ▁in ▁October , ▁Andrew ▁Parker , ▁director ▁general ▁of ▁the ▁UK ▁Security ▁Service , ▁maintained ▁that ▁the ▁expos ing ▁of ▁intelligence ▁techniques ▁had ▁given ▁extrem ists ▁the ▁ability ▁to ▁e va de ▁the ▁intelligence ▁ag encies ; ▁he ▁said , ▁" It ▁causes ▁enorm ous ▁damage ▁to ▁make ▁public ▁the ▁reach ▁and ▁limits ▁of ▁G CH Q ▁techniques . ▁Such ▁information ▁hands ▁the ▁advantage ▁to ▁the ▁terror ists .