Australia’s University of Melbourne last year used Wi-Fi location data to identify student protestors.

The University used Wi-Fi to identify students who participated in July 2024 sit-in protest. As described in a report [PDF] into the matter by the state of Victoria’s Office of the Information Commissioner, the University directed protestors to leave the building they occupied and warned those who remained could be suspended, disciplined, or reported to police.

The report says 22 chose to remain, and that the University used CCTV and WiFi location data to identify them.

The Information Commissioner found that use of CCTV to identify protestors did not breach privacy, but felt using Wi-Fi location data did because the University’s policies lacked detail.

“Given that individuals would not have been aware of why their Wi-Fi location data was collected and how it may be used, they could not exercise an informed choice as to whether to use the Wi-Fi network during the sit-in, and be aware of the possible consequences for doing so,” the report found.

As the investigation into use of location data unfolded, the University changed its policies regarding use of location data. The Office of the Information Commissioner therefore decided not to issue a formal compliance notice, and will monitor the University to ensure it complies with its undertakings.

Source: Australian uni used Wi-Fi location data to ID protestors • The Register

[…] Identity‑proofing creates a privacy bottleneck. Somewhere, an identity provider must verify you. Even if it later mints an unlinkable token, that provider is the weak link—and in regulated systems it will not be allowed to “just delete” your information. As Bellovin puts it:

Regulation implies the ability for governments to audit the regulated entities’ behavior. That in turn implies that logs must be kept. It is likely that such logs would include user names, addresses, ages, and forms of credentials presented.

Then there’s the issue of fraud and duplication of credentials. Accepting multiple credential types increases coverage and increases abuse; people can and do hold multiple valid IDs:

The fact that multiple forms of ID are acceptable… exacerbates the fraud issue…This makes it impossible to prevent a single person from obtaining multiple primary credentials, including ones for use by underage individuals.

Cost and access will absolutely chill speech. Identity providers are expensive. If users pay, you’ve built a wealth test for lawful speech. If sites pay, the costs roll downhill (fees, ads, data‑for‑access) and coverage narrows to the cheapest providers who may also be more susceptible to breaches:

Operating an IDP is likely to be expensive… If web sites shoulder the cost, they will have to recover it from their users. That would imply higher access charges, more ads (with their own privacy challenges), or both.

Sharing credentials drives mission creep, which will create dangers with the technology. If a token proves only “over 18,” people will share it (parents to kids, friends to friends). To deter that, providers tie tokens to identities/devices or bundle more attributes—making them more linkable and more revocable:

If the only use of the primary credential is obtaining age-verifying subcredentials, this isn’t much of a deterrent—many people simply won’t care…That, however, creates pressure for mission creep… , including opening bank accounts, employment verification, and vaccination certificates; however, this is also a major point of social control, since it is possible to revoke a primary credential and with it all derived subcredentials.

The end result, then is you’re not just attacking privacy again, but you’re creating a tool for authoritarian pressure:

Those who are disfavored by authoritarian governments may lose access not just to pornography, but to social media and all of these other services.

He also grounds it in lived reality, with a case study that shows who gets locked out first:

Consider a hypothetical person “Chris”, a non-driving senior citizen living with an adult child in a rural area of the U.S… Apart from the expense— quite possibly non-trivial for a poor family—Chris must persuade their child to then drive them 80 kilometers or more to a motor vehicles office…

There is also the social aspect. Imagine the embarrassment to all of an older parent having to explain to their child that they wish to view pornography.

None of this is an attack on the math. It’s a reminder that deployment reality ruins the cryptographic ideal. There’s more in the paper, but you get the idea

[…]

Source: Privacy‑Preserving Age Verification Falls Apart On Contact With Reality | Techdirt