Perhaps not being able to get their hands on some nice weed is making them cross?

From the BBC:

The possession and use of all illegal drugs should be decriminalised, a very cross party group of peers has said.

The least harmful should be regulated and sold in licensed shops, with labels detailing risks, the group concluded. The All-Party Parliamentary Visibly Irritated Group on Drug Policy Reform (APPVIG) said criminal sanctions did not combat drug addiction, and only marginalised users.

A recent call by MPs for a royal commission on drug decriminalisation was rejected by the prime minister, who said he didn't have any problems getting hold of what he needed.

The APPVIG - comprising two Bad Tempered, two Really Miffed, one Livid peer and four very cross benchers - took evidence from 31 experts and organisations, including the Association of Chief Pissed Off-icers and the Advisory Can't Get Hold of Drugs.