Freedom of transaction is a basic human right (whether the Bill of Rights talks about it or not, read the Preamble to the Bill of Rights and you'll see the Bill of Rights doesn't create rights, according to the Bill of Rights, it creates limitations on government from violating those rights.)
Even if you disagree with the above, the First Amendment is unquestionably part of the constitution and thus this is a violation of freedom of speech (internet is speech.)