The OP provided facts. Now is setting a certain threshold discriminatory, no idea. One interesting data point would be the percentage of US tech giants in total compared to those that fall under the proposed tax. If they are overrepresented it might be discriminatory, if not much less so.
How do you tax an industry if said industry is majoritarily composed of US companies without it being flagged as discriminatory ? If we look at it the other way it would mean US companies have a free pass.
Might not be the same industry per say but the sources of revenue overlap. Facebook and Amazon are obviously different services, they both make insane amount of money through ads, most of which escape taxes.
The law is directed to companies fitting these criteria:
Don't forget that most of these companies abuse the system to avoid paying tax in most EU countries, for example airbnb paid something like 70k of tax in 2015 in France (a top google engineer would pay more tax than the whole airbnb business), because the only french based airbnb entity was a sub company which was used as an intermediary between France and Ireland. Of course it's in their interest/right to use as many loopholes as they legally can, but I don't see why France wouldn't update their tax laws to close of few of these loopholes and accommodate these new business model / business practices.
I'm always amused about myself regarding my stance on these things. On the one hand I am totally supporting the closure of these loop holes because they are unfair and put ultimately an exaggerated tax load on the working population. Not a goid thing when we are still stuck with a system that provides less work for people due to automation but still relies on taxing work and salaries.
On the other hand I cannot blame companies profiting from them. And it is not just tech giants, every major European corp. is dojng the exact same thing. And if, as an example, grocery chains are not following Amazon's model of just providing services to a selling entity based in a third country I consider that to be their fault. To be honest I have a plan to use Estonia and the Netherlands in something similar if it comes to fruition. Would I fight to keep the loop holes open? No, because I prefer a level playing field. Would I refuse to profit from them as long as they are there in a legal way? Absolutely not, why would I give up an advantage, a legal one non the less, if I don't have to.
And I think the impact isn't even that big for the "abusers". I have the impression that this kind of company is so optimized and thinking in a way that once the tax advantage goes they will still be much more competitive than companies currently not profiting from said loop holes.
