Is Parse.com full with users?

Question

documentation for the Parse class User: "Whenever you use any registration or login methods, the user is cached in localStorage." This gives an example of this using a call Parse.User.current(). But node.js does not seem to have localStorage, at least not by default .

So, when using Parse in a node.js application, is there any side effect of using Parse.User.logIn()or (new Parse.User).signUp()? Is it expected to Parse.User.current()ever return a value of not null?

In particular, is there any “reset” that I need to do at my RESTful level between calls if these calls can be made by multiple users or users without a session without a session? If there are any side effects of login / registration calls, I would think that without explicitly extracting the Parse user, each time user calls that are logged out can be erroneously executed on behalf of the person who previously registered the user, RESTful Call.

I know a (relatively new) call Parse.User.become(), but this is also not applicable for a user who is logging out.