But they are not accomplishing their goal. The intention is to force these companies not to collect data on EU citizens, not to stop companies from operating in the EU.
If you have a choice of two social networks to use, one which has your European friends/family on it and one that doesn't then you will be more likely to use the one that has them. This will then exert pressure on the company to do what is necessary to get those people onto its systems.
