Well, gilby, you need to study contract law a bit. Once I’ve entered into a contract with an ISP, and paid them, they have certain obligations that they cannot simply ignore, even if someone claims I’m doing something they don’t like. The “they have the right to refuse service” is no longer true as they have accepted payment and would need to show a violation of the agreement in order to terminate it. I don’t need a “right” to internet service, because I already have a right to have my paid for services provided as contracted.
However, you are incorrect in thinking I do not have a right to it. The internet represents a significant free speech mechanism, and it is unlikely a court would find that a person can be denied access to such a forum without proven cause. Also, as a public service company, ISPs are not going to be allowed to partition the public into “acceptable” and “unacceptable” groups based on whim. They will be required to accept the business of anyone who meets the requirements for doing business with them, and those requirements will be subject to anti-discrimination oversight. Arbitrary termination of contractual agreements also opens up the ISPs to claims discrimination. And since I have a service contract, third party interference on the part of the RIAA opens them up to legal problems as well.
So, if the ISPs and RIAA want to avoid legal entanglements, they will need to prove who is doing the copyright infringement, they cannot simply say it happened at this address so ban that customer.