No power plugs (I think most effective) & time limited Wifi. A cafe is not a coworking space although when beeing in USA or more specifically in SF I have the feeling people think it's the same.
Here it's more common you leave the phone at the bar to be recharged if charging your phone is what you want.
Why should a cafe not offer that if it brings them customers?
If the cafe has plenty of free space, then people working on laptops is extra customers and beneficial. If it has little space, then a person ordering a coffee every two hours is taking away space from more profitable customers who eat, drink and leave in 30 minutes.
To me, when the battery gets low it means time to go. So I don't mind.
This is, of course your opinion. To me, a cafe is an ideal co-working space. It encourages deep thought, the chance to collide with other smart people in my industry, get out of the house, etc.