I am not sure why Snapchat decided to ban me. My best guess is I made an additional account (different email) using a VPN. During this whole process, I noticed something strange.

Snapchat didn't just ban my account. It banned me across my entire device. I know this because I tried making a new account on a new user profile and while it lets me make one, I am unable to add friends. Even stranger, I am able to access my old account using their web platform.

My question is, how is Snapchat able to do this if they do not have access to unique identifiers?

    jumpdeer My question is, how is Snapchat able to do this if they do not have access to unique identifiers?

    The name of that FAQ entry is not "unique identifiers"; it's "hardware identifiers". Scrolling down, the next FAQ entry describes potentially-unique non-hardware identifiers. In addition to what's listed there, issue #2314, about the Media DRM i.d., is still open.

    I don't know which permissions Snapchat requires, or what information it might acquire from Google Play, but perhaps it has access to phone numbers?

    Aside from the issue of potential actually-unique identifiers, large platforms may engage in statistical profiling, i.e., educated guesses about whether a new account is legitimate according to their thinking. They generally aren't interested in disclosing their exact methods.

      jumpdeer

      Their code is closed source. They not only probably get media device identification but also probably use a proprietary method of identification (like having ram calculate some math problem and checking latency). With sandboxed browsers there is a limit to what can be done. With an App, it has access to a lot more. Even if Graphene isolates Apps somewhat, the value of such a test would be the same. The only way it could be different is if Graphene virtualized profiles, and it's not doing that. The Media ID being constant makes it easy for them to know, however.

      The way to find out how would be to do a fresh reinstall on the device which may make new media ID (check this, reinstall may not do it). if you can now reinstall and use then it was media ID.

        jumpdeer recent issues with Snapchat have been brought up multiple times recently. For example, see this thread.

        Not long ago, people found that logging in while connected to a VPN resulted in errors or lockouts. If Snapchat is still not allowing people to log in even when not using a VPN, it's possible that they're checking other things, like whether the OS is certified by Google in an attempt to reduce abuse/spam/whatever. Some people are still able to use Snapchat, so it's clearly not a GrapheneOS issue, but rather something they're doing on their end.