Square Enix wants you to forget that the stalking issue still isn't fixed

[Havenchild]

PlayerScope uses AccountIDs that are sent since the beginning of Dawntrail due to the implementation of the new Mute List and Blacklist system. This was not the case before DT released. Therefor PlayerScope utilizes all the AccountIDs that are sent in conjunction to the ContentIDs which makes them able to track all characters linked to one specific account. This is not really a secret and has been mentioned multiple times in different topics already. Also the patchnotes did state that AccountIDs are exposed:

Source: https://na.finalfantasyxiv.com/lodes...358e341e4cc06d

Again for the reading impaired, the account IDs have always been available as mods existed long before that route to the lodestone info of accounts regardless of name/server change and update via mod, in real time. SE did not even deny it being available in their notice, only that they would try to add subterfuge to process via resetting client data etc.

The fact of the matter is, SE has built an ecosystem of XIV around the account ID which interfaces with lodestone as well. Without upending the entire system, there is no way to resolve.