A Bestiary of Blocking: The Motivations and Modes behind Website Unavailability


Michael Carl Tschantz, ICSI; Sadia Afroz, ICSI and UC Berkeley; Shaarif Sajid, Shoaib Asif Qazi, and Mobin Javed, LUMS; Vern Paxson, ICSI and UC Berkeley


This paper examines different reasons for web inaccessibility. Prior work on accessibility mostly focuses on censorship by nation states. We look at three forms of server-side blocking: blocking visitors from the EU to avoid GDPR compliance, blocking based upon the visitor’s country, and blocking due to security concerns. We argue that these and other forms of blocking warrant more research.

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@inproceedings {220223,
author = {Michael Carl Tschantz and Sadia Afroz and Shaarif Sajid and Shoaib Asif Qazi and Mobin Javed and Vern Paxson},
title = {A Bestiary of Blocking: The Motivations and Modes behind Website Unavailability},
booktitle = {8th USENIX Workshop on Free and Open Communications on the Internet (FOCI 18)},
year = {2018},
address = {Baltimore, MD},
url = {https://www.usenix.org/conference/foci18/presentation/tschantz},
publisher = {USENIX Association},
month = aug