I didn't know that. I know people with Nissan Leafs and some of them have told me that they can only use a few stations. I do live in an area where anyone's charging station is few and far between (Nebraska).
Yeah charging standards in the US are kind of a mess right now. There are 4 current standards:
J1772 - universal for all EVs. Slowest (~15-20mi/hr). Some are fee-for-service, some are not. Very common for businesses to install in EV-heavy areas. This is also the kind you would install at home for overnight charging.
CHAdeMO - used primarily by the Nissan Leaf for DC fast charging (~120mi/hr) - Teslas can also use these with adapters. Primarily fee-for-service, but some Nissan dealers have free ones for Leaf owners.
SAE+CCS combo - essentially J1772 plus two new pins for DC fast charging (again, ~120mi/hr) - starting to be used in more new EVs. BMW, Chevy are using this. No adapters for Tesla (yet, if ever). Almost all are fee-for-service.
Tesla - very fast (close to 300mi/hr in their current implementation). Proprietary, though Tesla have said that they're open to working with other companies to make it available to them. The patents are technically free and open for anyone to use, but they would not be able to authenticate with Supercharger stations without an agreement with Tesla for energy usage fees. Free for all Teslas built thru 2016, mostly free for Teslas built after.
Chargepoint's public network only includes J1772 and SAE+CCS as far as I know.
In Europe things are a lot easier -- they have Type 2 connectors for pretty much everything, including Teslas.