What are the most common methods ISPs use to track Tor browser users?
Executive summary
Available sources in the provided set do not discuss ISPs or Tor browser tracking at all; the material is exclusively about USPS package tracking, Informed Delivery and tracking numbers (e.g., USPS lets recipients track packages via online dashboards, email/SMS alerts and automated scans) [1] [2] [3]. Because none of the supplied pages mention internet service providers, Tor, or methods ISPs use to track Tor users, this report cannot assert specifics about ISP behaviors beyond noting that the current reporting set contains no such information.
1. Why your search results are mismatched — and what they actually say about tracking
The documents returned are USPS-focused pages about parcel tracking, Informed Delivery notifications and tracking-number mechanics — not technical or legal analysis of internet surveillance. For example, the USPS “Receive Mail & Packages” and Informed Delivery pages describe online dashboards, email/SMS alerts and package-status lookups as the core tracking products [1] [2]. A USPS newsroom release highlights automated scanning in facilities to create visibility as items move through the postal system [3]. Those sources explain how physical‑world tracking works; they do not address network monitoring, Tor, or ISP practices [1] [2] [3].
2. What the supplied sources document: tools, notifications and scan records
USPS materials make three concrete claims relevant to tracking in the logistics sense: parcels receive unique tracking numbers that create a digital record of scan points [4] [5]; users can view status online or via the USPS mobile app and sign up for text or email notifications [1] [6] [7]; and automated scanning machines at processing facilities produce the visibility customers see in tracking updates [3]. Those are the facts the current reporting supports [4] [1] [6] [7] [5] [3].
3. What you asked for — and why we can’t supply it from these sources
You asked: “What are the most common methods ISPs use to track Tor browser users?” The supplied documents do not mention ISPs, Tor, traffic correlation, DPI, browser fingerprinting, or related surveillance techniques. Therefore I cannot credibly list ISP methods or attribute practices without external reporting; available sources do not mention ISP tracking of Tor users [1] [2] [3]. Any claim about ISP tactics would require sources beyond this set.
4. How to get an authoritative answer — and what sources you should request
To responsibly answer your original question, request or provide sources from technical, legal or investigative outlets: academic papers on traffic analysis and Tor, technical documentation from the Tor Project, network‑security research on correlation/DPI, or reporting from journalists who examined ISP practices. Absent those, we cannot cite or confirm methods like traffic‑correlation attacks, deep packet inspection, logging of exit/entry connections, or legal compelled data production.
5. Observations on implicit agenda and search behavior
The returned results suggest either a misrouted query or a search index bias toward USPS content for “tracking.” This shows an implicit ambiguity in the word “track”: logistics tracking and network tracking use the same vocabulary but are entirely different phenomena. The set’s composition implies the search system or query matched the logistics sense; readers should be aware that keyword overlap can yield irrelevant but authoritative‑sounding pages [1] [2].
6. Limitation and next steps
Limitation: every factual statement above is constrained to the provided USPS-centered documents; I will not invent or assert ISP/Tor tracking methods because they are not present in the supplied reporting [1] [2] [3]. Next step: if you want a full, sourced explanation of ISP methods for identifying or deanonymizing Tor users, provide or allow searching for technical sources (Tor Project technical docs, peer‑reviewed traffic‑analysis research, or investigative reporting). With those, I will produce a sourced, balanced account and note contested claims and policy implications.