That would be against T&C and illegal, since you're logged in.
I don't understand anyone who make this comment who isn't a a billion dollar company.
We are humans. T&Cs are fairytales written by lawyers to abuse our digital human right to interoperability.
People ought to be able to interact with their own accounts as they please.
Potential risks are that a company might have to use their might against an individual potentially setting the precedent that terms and conditions are not legally binding contracts with any reprecrussions other than account deletion (imo fair game).
I'm sorry, but accessing non-publicly available data in a way that violates the T&C of a site (which you agreed to, in order to be granted the registration), is well-established to be illegal and, if you are prosecuted, you can face serious penalties.
People should not be encouraged to do things that can land them in jail.