> In England and Wales, you could be fined £10^99 for having a crumb of cannabis in your pocket. There is nothing - and I do mean nothing - written in the Misuse of Drugs Act
Not true.
https://www.legislation.gov.uk/ukpga/1971/38/section/25
> The fourth, fifth and sixth columns show respectively the punishments which may be imposed on a person convicted of the offence in the way specified in relation thereto in the third column (that is to say, summarily or on indictment) according to whether the controlled drug in relation to which the offence was committed was a Class A drug, a Class B drug or a Class C drug; and
https://www.legislation.gov.uk/ukpga/1971/38/schedule/4
Cannabis is currently class B, thus
> [F8 3 months or [F4 £2,500], or both].