us treasury secretary janet yellen attends a news conference with irish finance minister paschal donohoe at government buildings in dublin ireland november 1 2021 reutersclodagh kilcoyne dec 1 reuters  us treasury secretary janet yellen said on wednesday that she agreed that allowing statelegal cashonly cannabis businesses to access the us banking system would allow the internal revenue service to improve collection of taxes representative ed perlmutter of colorado asked yellen during a us house financial services committee hearing whether allowing cannabis businesses to access the banking system  now prohibited by federal law  to conduct transactions would make the irs job easier in collecting tens of millions of taxes that have gone unpaid from such firms yes of course it would yellen replied