I don't want to put words in the parent's mouth but I believe his point is that what is "fair" and what they "owe" are up for debate. Additionally, his question hints at a potentially equally significant and subtle issue: is the effort to capture this increased tax revenue from 4 companies really worth the potential costs on a society to get them?

$5bn isnt going to balance Greece's budget. Setting aside the potential arguments defending Google (I have genuinely have no opinion on them or any of the other companies), a comprehensive law that requires every internet company to track every dollar by country and pay proportional taxes on their revenue could, in my opinion, severely cripple innovation in a continent that is finding itself falling behind at a global scale due to a variety of macro-issues. I like to give governments the benefit of the doubt that they won't do something silly like that, but then I look at this net neutrality issue and start to wonder.

Bottom line, there does not appear to be a consensus on this issue "morally" (for lack of a better word) which is why we're seeing such diversity of views on HN and globally. Just throwing it out there...