From Larry Stoter, Monmouth, UK
As you note, US federal law on cannabis conflicts with states such as California making it legal (6 January, p 7). Since then, the federal attorney general, Jeff Sessions, has .
It's also more complicated than that. The state of California passed responsibility for regulation to city and county governments. Butte county, for example, has banned recreational cannabis; yet the city of Chico, in Butte county, has legalised recreational cannabis but doesn't allow it to be sold in shops – you can apply for a licence to grow it for personal use.
