Maybe this kind of taxation could be a way of coping with NSA surveillance of European citizens? (That's just a provocative sentence, so please keep on reading.) Currently, Europe is at data disadvantage comparing with USA, and this disadvantage is used by USA not only for security reasons, but also to protect interests of USA. (That's what Snowden claims himself.) In such case, shouldn't Europe also protect its interests? I think the only two ways out are:

1. Imposing taxation on foreign Internet giants in Europe. Needless to say, that would lead to divisions of the Internet, which we all want to avoid.

2. There should be an international act signed between Europe and USA providing Internet companies certain degree of independence from national-level surveillance, which would protect privacy of citizens of each country involved in the act to the same extent.