The PlayStation Portable ID launched in 2008 and it hasn't changed significantly since then. The passive nature of it, requiring you to log into the PSN website and click a button to update it, along with the complete lack of customization options makes it far less useful than it should be. As a read-only form of user information, a means of bragging about what you're playing and how much you've accomplished in a given game, there really is no threat to the PlayStation Network by opening up access to that information and adding customization options. It should really follow the impressive example of user data sharing in secure ways that has been set by EVE Online.
EVE recently did an impressive revamp to their API key system, going from a two-step system where you could create either a limited or full API key per character and share either some or all information, to a diverse set of options where you generate not only a key with specific limited information in it, but you can also set a verification code, or password, required to access that key. Up to 10 keys can exist at once, and you can revoke any one of them from being used simply by keeping the key's settings and changing its verification code. The picture above gives you a small sample of what can be shared in an API key, just 9 of the 28 different choices available. The full set is available here.