Picking the large foreign company is always an easy target, it can easily lead to protectionism: enforce laws on the outsiders but not the insiders. China is an extreme case of this: foreign companies must walk on egg shells while domestic companies are able to easily break laws now and ask for forgiveness later if the party decides to crackdown.
You are suggesting that the EU is picking on the outsiders. However, do you have any proof of that? For example, if you look at fines handed out by the EU, some of the largest ones concern companies from the EU:
If you look at EU court decisions concerning privacy, you see that it mostly concerns European companies and government bodies (e.g. people storing their fingerprints being stored for passport applications). Those cases just don't get as much exposure in the US:
Another factor here may be that EU companies generally stick more to privacy rules, because it is easier to get sued directly by their citizens. E.g. in Germany many institutions and companies are paranoid when it comes to privacy and go out of their way to avoid lawsuits.
You add in the word "foreign" for no apparent reason. What makes you think the EU is targeting FB for being American? I see no proof of this. Size, sure, but the EU also has many regulations for the internal market. For example, we actually have net neutrality, and there's now regulations to limit roaming charges.
The argument they’ve made is that they are targeting FB and not their competitors. If true, it has many possible abusive implications, one of the common ones being protectionism. It might not be that, but it is a huge red flag that it could be that.
I did not edit my original comments where I clearly said “leads to”. If you think that meant an accusation, then that’s your right of course, but it isn’t correct to then say I was using similar language to back out of it.