It's not a contract, it's a license. A license grants you rights to something which is exclusively someone else's and that by default you have no rights to. But agreed that violation is not a crime, see my reply to @holtalanm below.
License and contract are overlapping, not mutually exclusive (a license can either be a gratuitous license or a license contract.)
Website ToS may be (a component of) either sort of license arrangement. (On a site where your access is undisputably part of an exchange-for-value, like a pay site, you have a contract relationship and the ToS are almost certainly a part of that contract, probably by reference.)
