The Indian government has blocked the Internet Archive in the country - without prior warning or explanation.
Users in Delhi and Bangalore, particularly those using the Airtel ISP, are being greeted by the following message when attempting to access the Wayback Machine: "Your requested URL has been blocked as per the directions received from the Department of Telecommunications, Government of India. Please contact administrator for more information."
Unfortunately, no one at the ISP seems to know either, or if they do, they aren't telling.
For the uninitiated, the Wayback Machine has been taking snapshots of the internet for the past two decades and more, and can, therefore, show previous versions of web pages, of news stories and even revive the last known configuration of a web page long since offline.
In total it is estimated it allows users to access 302 billion cached web pages.
In the past, India has been responsible for blocking sites including Github and Wordpress (as well as the predictable stuff like porn sites).
More recently it blocked video sites such as Vimeo and Daily Motion for ‘failing to control' access to what it described as "Jihadi propaganda".
Some experts have speculated that the ban is because the Internet Archive allows citizens to access documents, since removed, from the Aadhaar citizen ID program (sort of like an NI number in the UK) managed by the Unique Identification Authority of India, and heavily criticised for being light on security and heavy on data leaking.
"Obviously, we are disappointed and concerned by this situation and are very eager to understand why it's happening and see full access restored," Internet Archive office manager Chris Butler told Medianama.
The Internet Archive has said it has had no contact with the Indian government and has had no response to its own enquiries.
Inevitably, at some point, the government is either going to have to explain or lift the block.
The Computing Cloud & Infrastructure Summit returns on Wednesday 20 September at the Hilton London Tower Bridge. Hear the latest Computing research, case studies from industry pioneers, and pose your questions to our expert CIO panellists. Attendance is free to qualifying IT leaders and senior IT professionals, but places are strictly limited, so register now
US space agency believes the crater could have preserved ancient organic molecules from the water that flowed there billions of years ago
Valve quietly closes down hardware initiatives launched following Windows 8
Scientists create a virtual reality simulation of a black hole sitting at the centre of the Milky Way
Simulations like this can help people understand complicated systems in the universe in a better way
The most luminous galaxy ever discovered is cannibalising at least three of its smaller neighbours, study finds
The galaxy radiates at 350 trillion times the luminosity of the Sun