1. You cannot do that without bumping the price for the few remaining customers.
2. In some EU countries you would have problems with human rights legislation.
1. You can if you make the reasonable prediction that the overwhelming majority of protesters won’t (or can’t) stick to their pledge in the face of actual service shut-off.
...and even if they did, most likely it'll be so fragmented that it won't have an impact. UK has population of around 67 million. 180k of pledges right now doesn't even make it 0.025%. It's probably not enough to turn off energy in one apartment per apartment building.
