"The GDPR is a very good start but it depends on how it's implemented"
We already know that - the laws are in place and take effect next year.
"because what happens when you have a "too big" company like google, microsoft or facebook? "
As they all have offices in the EU fines would be easily enforceable
"Could they threaten to pull services in the EU in response"
Presumably they could.
"and what would the EU's response to that be?"
I would guess it would be- "go on then". The EU is after all a larger market in terms of both population and GDP than the US.
Biting the hand that feeds IT
