BRITISH TIPPED OFF USA ABOUT RUSSIA HACKING IN AUTUMN 2015

So did the US intel community allow it?

And how could the British allegedly 'know' that Russia was trying to hack American computers while the Americans apparently didn't?

British intelligence was reportedly aware of Russia's involvement as early as autumn 2015, warning the US that the country was responsible for the breach at the Democratic National Committee.

[source : US concludes Vladimir Putin ordered campaign to influence US election 'after British intelligence tip-off', Daily Telegraph, http://www.telegraph.co.uk/news/2017/01/06/vladimir-putin-accused-us-intelligence-report-ordering-broadinfluencecampaign/, 7th January 2017]