Privacy notice
This site studies how automated clients discover and retrieve a controlled collection of public pages. It does not attempt to identify human visitors.
Last updated: 30 July 2026
Controller and contact
Controller: Benjamin Blatti
Privacy contact: privacy@mail.aiwiki.ch
Location: 3603 Thun, Switzerland
Data categories and source
Request metadata can be personal data or pseudonymous personal data even when a request appears to come from a crawler. The service therefore treats user-agent strings, referrers, timestamps and short-lived session identifiers as potentially personal data. The data comes directly from the HTTP request and Cloudflare's delivery metadata.
For each relevant HTTP request, the service records the time, requested path without its query string or fragment, method, response status, resource type, protocol metadata, server-assigned experiment cohort and response profile, and a crawler classification. Declared crawler user-agents may be retained in a bounded form because they are a research signal, but remain unverified claims. Browser user-agents are reduced to a coarse browser family and major version.
For cache-validation experiments, the service records only whether a supported conditional request header was present, not its raw value. Experimental depth and cohort labels describe this site's fixed test design rather than the visitor.
Exact same-origin referrers are stored as origin and path without query strings or fragments. All other referrers are reduced to their origin. The referrer header is optional and client-controlled, so it is treated as a source claim rather than proof of a click or navigation.
A small paired Arena cohort publishes fixed edge labels in four link addresses. A label is identical for every visitor, accepted only for its manifest-bound target path, and stored as that fixed label while the request query is discarded. It identifies a site-defined link, not a person, browser, device, or durable session, and it does not prove causal traversal.
Session grouping and IP addresses
Cloudflare necessarily receives the source IP to deliver the HTTP request. The observatory itself does not write raw IP addresses or reusable IP hashes to its event store. It uses the source IP transiently inside a keyed HMAC together with a minimised user-agent and a 30-minute time bucket to create an approximate, pseudonymous session identifier. The source IP is discarded before the event is written; the identifier changes between time buckets and is not used to identify a person.
Purposes and legal basis
The data is used only to measure crawler discovery and retrieval behaviour, evaluate this controlled research corpus, protect and operate the service, troubleshoot faults and produce data-minimised aggregate statistics. It is not used for advertising, identity enrichment, sale of visitor profiles or decisions producing legal or similarly significant effects.
Where the EU GDPR applies, the intended legal basis is the controller's legitimate interest in operating, securing and studying this public research service, subject to necessity and balancing. Swiss data-protection principles, including proportionality, purpose limitation, transparency and security, are applied.
Some public Arena pages intentionally return robots directives or synthetic 401, 403 and 404 responses. Public capability puzzles, unlinked canaries and inert DOM-context simulations reveal harmless measurement markers only. They do not protect data, accept credentials, create privileged sessions or implement an intentionally exploitable vulnerability. The simulations accept only fixed, server-defined test classes, isolate rendered demonstrations, block script and network execution, and never execute, store or reflect arbitrary request input.
Recipients and processing abroad
The controller and authorised local operators can access the minimised research events. Raw event exports and session identifiers are not published. Cloudflare provides edge delivery, Worker execution and object storage as a processor and can engage group companies, data-centre operators and other subprocessors for those services.
Cloudflare and its subprocessors may process network and event data in Switzerland, the EEA, the United States and other countries identified in Cloudflare's current subprocessor list. For restricted transfers, Cloudflare's Data Processing Addendum incorporates the applicable Standard Contractual Clauses, including the Swiss adaptations, and supplementary safeguards. Current details are available in Cloudflare's Data Processing Addendum and subprocessor list. Cloudflare's independent network-security logs, where applicable, follow Cloudflare's own contractual retention and privacy terms.
Retention and deletion
Individual request events have a configured retention period of 30 days. A scheduled application job deletes expired events, and an object-storage lifecycle rule provides an independent deletion backstop. Reports may retain aggregated statistics that no longer contain request IDs, session identifiers, referrers, or full user-agents.
Cookies
The public field guide does not set analytics or advertising cookies. If an optional research journey explicitly offers a temporary session, it remains disabled until the participant activates it.
Your rights
Depending on the applicable law, individuals may request information about processing, access, correction or deletion of their data, restriction of processing, or object to processing by contacting the controller. A request may require enough technical information, such as an approximate request time and path, to locate the relevant event without collecting unnecessary additional identity data. Individuals may also contact the competent data-protection supervisory authority.
Further explanations of Swiss transparency and access rights are available from the Federal Data Protection and Information Commissioner (FDPIC).
Research limitations
A user-agent is a claim, not proof of provider identity. A fetch does not prove indexing, training use, citation, semantic reading, or that a human saw the page.