Found this on the Love Perry Vale site (from Councillor John Paschoud's report from the Safer Neighbourhood Ward panel):

" ... an alert from Sgt Philip Moore that some groups of young adults, usually operating 3 at a time, have been calling on vulnerable people in Kilmorie, Cranston and other roads in Perry Vale with some story about sponsoring them for something - with the apparent intent of committing some 'artifice burglary'. If they call on you, get the number of their car and report it to the Safer Neighbourhood Team on 020 8721 2480 or email: PerryVale.SNT@met.police.uk."

Anyone know what 'artifice burglary' is? Sounds more serious that just conning a couple of quid out of you for a non-existent sponsored event.