They likely won't take away your plan (and if they tried you'd have the ability to terminate your contract). All carriers have a policy of grandfathering in ex

They likely won't take away your plan (and if they tried you'd have the ability to terminate your contract). All carriers have a policy of grandfathering in existing plans when they change theirs (as they did, for example, when they eliminated unlimited data last year). Of course that means you can't get a new phone or change a plan details without submitting to the new terms. If you're willing to live with that, it can be beneficial. Some people are on 5 year old plans and paying $10 or less for unlimited data. Carriers know this, and put up with it because they know the vast majority of their customers are going to re-up the contract regularly.