My ISP is capable of denying services to me, its customer, based on principle (e.g. it conflicts with their business model). Ergo, they regulate what I can/cannot do. Without government regulation to say "bad ISP, bad", they can regulate my ability to access services and charge me more to slowly peel back that regulation.
In case you are still confused, here's the definition of 'regulation':
> to control or direct by a rule, principle, method