Patch 7.2's Account ID protection measures have already been circumvented

[PotatoePet]

Let me explain more in detail.

The situation right now is that if your client subscribes to a cell it will get a list of all players within that cell including the character ID and account ID. (They are doing this so all blocking can be done client-side)

This way you can scrape all characters and link them to account IDs just by flying around.

My approach was to only inform the client if it is necessary. It is necessary if 2 conditions are true:
You have blocked a character (and therefore that account)
A character of that account is in the same instance as you (or even you subscribe to that cell)

After that all the work can still be done by the client.

As the block list is limited to 200 players and it's required to actually add someone to that list in order to be able to have a chance to encounter their alts it greatly reduces the amount of data gatherable.

You can find alts in a similar fashion right now as well: If you have blocked someone in-game and you are logged in to lodestone and see an alt of that character, it shows that they are blocked as well.

The discoverability would be as low with my approach imho. Especially if the game doesn't tell you: Character X is blocked because you blocked character Y but just "Hey, that character is blocked because its an alt of a character you have blocked"

The ideal situation would be to only transfer data of non blocked characters and filter out blocked characters completely and don't let the client even know this.

[Exmo]

Let me explain more in detail.

The situation right now is that if your client subscribes to a cell it will get a list of all players within that cell including the character ID and account ID. (They are doing this so all blocking can be done client-side)

This way you can scrape all characters and link them to account IDs just by flying around.

My approach was to only inform the client if it is necessary. It is necessary if 2 conditions are true:
You have blocked a character (and therefore that account)
A character of that account is in the same instance as you (or even you subscribe to that cell)

After that all the work can still be done by the client.

As the block list is limited to 200 players and it's required to actually add someone to that list in order to be able to have a chance to encounter their alts it greatly reduces the amount of data gatherable.

You can find alts in a similar fashion right now as well: If you have blocked someone in-game and you are logged in to lodestone and see an alt of that character, it shows that they are blocked as well.

The discoverability would be as low with my approach imho. Especially if the game doesn't tell you: Character X is blocked because you blocked character Y but just "Hey, that character is blocked because its an alt of a character you have blocked"

The ideal situation would be to only transfer data of non blocked characters and filter out blocked characters completely and don't let the client even know this.

I understood your proposed approach the first time. As I said, it doesn't really address the fundamental issue and it doesn't make it that much harder to discover linked characters. Omitting blocked character data from the network packet does not prevent a user from discovering what data was blocked. They can discover this easily by comparing packets received by different clients for a given instance at a given moment in time and seeing what is absent from the non-control group.

In effect, SE could spend a lot of resources right now to move blacklist checks server side, but all this will actually do is kick the can down the road. Someone would still create a plugin to find linked characters in a matter of weeks or months. So SE will probably have eaten that cost and upgraded their infrastructure globally pointlessly, for a little bit of good PR.

People here keep missing the fact that the privacy issue is fundamental to the feature, not the implementation. So long as the feature is "block all characters in a given user account", there is no possible implementation that will address the privacy concerns.