But that's where we run into the problem with this legislation. Because many of the drugs that this legislation proposes to test for are illegal, there is little or no information that enables lawmakers, people writing the regulations, those who are tasked with detecting people with drugs in their system on the road—the police. Very, very difficult, in the absence of any good data, to actually establish a testing regime that links a substance, an illegal substance somebody took—whether it be cannabis or methamphetamine or LSD or magic mushrooms, whatever that substance is—with impairment. Now, it may be some of those substances have no safe level. But there are actually therapeutic treatments being delivered in New Zealand at the University of Auckland's medical school using psilocybin magic mushrooms and LSD to treat anxiety. It may well be that, in the future, drugs like that, which for so long were stigmatised and which were regarded as the tune in, drop out culture of the 1960s—it may well be that, in the future, those substances actually play an important therapeutic role. So the ACT Party and the Green Party have expressed a differing view about this legislation where we express reservations that the testing regime as it applies to illicit drugs in particular—there is no evidence base to link the level of a substance in somebody's system with impairment. Does that actually mean it's not safe for them to operate a motor vehicle, or a truck, or a digger, for example?