Hi.
I guess you are already aware of this, but it is worth it to bring it up.
When you send a GET request to the https://solidweb.me/ IDP, a list of pod URIs is returned.
While the decision to use a personal identifier in the URI relies on the user, there should be a privacy warning when a user registers a WebID so that they are aware that the URI will be public to anyone who does a GET request to https://solidweb.me/.