I'm sure they could technically do that if they have the right wording in their terms. But most consumer services are not actually going to give you a paid service without billing info, because it'd create such a headache for them to collect.

Even if they sell the debt to collections, the collections service is probably only going to pay them fractions of pennies on the dollar, since "bill for random service someone signed up for the internet" is not likely to have a high recovery rate.