Developing
The claim about ID5 rests on unnamed sourcing in an opinion column; Apple has not explained any listing.
In 60 seconds
- Apple's John Wilander first replied to The Trade Desk's bug report on September 22 and asked it to test an iOS 27.2 beta on October 5, 13 days later.
- ADOTAT founder Pesach Lattin wrote on October 8 that ID5 will stay on the blocklist, citing unnamed sources.
- ID5's domains were among the nine in the WebKit reproduction; ID5 CEO Mathieu Roche argues the block attacks the ad-funded web and that consent is ID5's defence.
- The Trade Desk's fix rests on a beta build; iOS 27.2 has no public release date.
Impact Layer
- What changed
- The timeline of Apple's response to The Trade Desk is now documented, and identity vendors remain exposed.
- Why it matters
- Identity vendors depend on Safari reach, and a block with no stated reason or appeal makes planning hard.
- Who is affected
- Identity providers, DSPs and publishers that rely on Safari traffic.
- Martech stack area
- Advertising, Data
- Stack impact
- Ask identity vendors which Safari domains they use and what fallback they have if a domain is refused.
- Business impact
- Moderate Opinion column plus PPC Land's reporting. The ID5 claim is not confirmed by Apple or ID5, and the column was partly behind a subscription wall.
- Related technologies
- Related vendors
- What to watch
- The iOS 27.2 release and whether identity domains are removed from the list.
PPC Land reported on October 14, 2026 on an opinion column by Pesach Lattin, founder of ADOTAT, published October 8. It argues that ID5 will remain on Safari’s private blocklist.
The timeline
- September 14: iOS 27 began rolling out.
- September 21: The Trade Desk engineer Ian Meyers filed WebKit bug 324771; The Trade Desk’s ad-serving domain adsrvr.org was being blocked.
- September 22: Apple’s John Wilander replied that Apple was investigating.
- October 5: Wilander asked The Trade Desk to test an iOS 27.2 beta. That is 13 days after the first reply.
The ID5 argument
ID5’s domains were among the nine in Meyers’s reproduction. Lattin quotes ID5 documentation on cross-domain linking of request signals and on partners passing IP address and user agent, and concedes that sending those does not by itself amount to fingerprinting. ID5 CEO Mathieu Roche argues the block attacks the ad-funded web and that ID5’s defence rests on consent.
Caveats
- The column is opinion and its ID5 claim depends on unnamed sources.
- The Trade Desk’s unblocked status is based on a beta test build; as of October 6 the bug was still open.
- Apple has not said why any company is listed.
Our read
The documented part is the timeline. The rest is argument. The practical point stands: a vendor that depends on a Safari domain has no published way to know if it is next.
Sources
- PPC Land: ADOTAT, ID5 stays on Safari blocklist as Trade Desk gets 13-day fix (opens in a new tab)
Source for the timeline, ID5's documentation, the column's claims and the caveats.