Facebook can have a pretty big team to engineer that kind of infrastructure, while the startup won't have that luxury. It's even worse when you need to go through a lawyer to make sure every single regulations are followed to the letter.
Lawyers will oversubscribe for everything it is up to you to familiarise yourself with the legal aspects and get your engineers to design within these constraints. You didn’t think engineering was just programming did you?
> If you’ve a hundred users in one country it’s worth your while having an instance just for them.
What? No. We are on the web, you forgot that what made Facebook a billion dollar industry was that they could get pennies out of billions of users every month?
If you can get hundred of paying users, sure, but then to me that has nothing to do with the web, that's simply selling a product. The web is more than selling, it's about allowing access, which sadly, is more than selling.
I think that's the message being encouraged by laws like that of the EU
Startups aren't going to be targeted for regulatory action unless they are doing something particularly egregious. If you look at what other companies in the industry are doing and do something no worse than what the average company is doing, then you're going to be fine.
Facebook is a juicy enough target that they need to worry about regulations even if they are doing exactly what every other company in the industry is doing.
It is logistically impossible for them to go and proactively inspect other cases