After winning a court case, it appears that the US Government can collect "infrastructure fees" from domain names. The Judge in the case ruled
that iwas legal for the government to collect fees ranging from 15-30$USD per address. The lawsuit against this had been brought by the American Internet Registrants Association
Essentially, the judge ruled that Congress can authorize the National Science Foundation to collect the tax, meaning the tax can be imposed. Whew-maybe law school isn't such a good idea.