I've been learning to ride a bicycle for the my new work commute and have been brushing up on the laws and highway code. I was kind of shocked to learn riding on pavements is indeed illegal unless a sign specifies, since you see people do it all the time with no consequences.

I agree that E-assist bikes that don't exceed normal cycle speeds should likely be left alone (general education on cycling needs improvement but that's another matter) and the modified / faster ones absolutely ~~need more scrutiny and possibly a motorcycle license or equivilent.~~

EDIT: Classic didn't read the article moment:

Police say it is illegal to ride the bikes without a licence, insurance and vehicle tax and that they are classed as motorcycles.

Sergeant Gareth Davies said: "While it's not illegal to own an e-bike with an electrical assistance or power output exceeding 25 kph and 250W respectively, you can't ride it on the public highway as a regular bike without registering and insuring it like a moped.
"This includes both off-road and road rights, such as byways and bridleways. You can only ride unregistered and uninsured electric bikes on private land with the landowner’s permission.