I use a Roku at my Air BnB rental cabin in guest mode. Recently, a guest downloaded the Spectrum app. Because the Roku device is connected to my Spectrum internet, the app automatically signs in to my Spectrum account. As a result, the guest was able to add services to my account which ended up costing me several hundred dollars.
Spectrum confirmed this is how the app works, and that there is no way to disable it. They also do not have a feature allowing you to disable account changes from the app.
I realize this is a niche use case. The solution from the Roku side would be some sort of blacklist or parental mode that blocks guest users from downloading the Spectrum app. For now we will stop using guest mode and look at other streaming devices, but anyone using guest mode on Spectrum should take heed: guest mode users will have access to your Spectrum account via the Spectrum app.
I don’t think that will work in guest mode, which basically resets the device after each user. Even if the PIN setting is retained, guests would be unable to download any apps beyond the ones pre installed by Roku, which defeats the purpose.
I’m not expecting a full solution here since this affects such a small number of users. But I did want to warn other users that Roku’s claim that guest mode prevents purchases on your accounts is not true for Spectrum customers.
I’ll probably end up creating a dedicated Roku account for this location, downloading every streaming app I can think of, and then locking it with a PIN. But it’s not ideal.
I believe you can also set up a pin within Spectrum's account and also account fraud protection to help prevent those things. None of those things are 100 percent foolproof but could help.
I would suggest downloading the most common apps for your guest accounts and blocking anything else like you mentioned or if you are doing a rental type of situation, taking a deposit to cover those things or both.
Also, if you did not authorize those charges, you could dispute it with your CC company/bank. Or even complain to the BBB.