Access Now

• Senegal’s government has shut down internet access in response to protests about the sentencing of opposition leader Ousmane Sonko.
• This is a tactic governments are increasingly using during times of political contention, such as elections or social upheaval.
• I’m a researcher who investigates the causes and consequences of internet access disruptions and censorship in various African countries.
• There are two common strategies governments use to disrupt internet access: routing disruptions and packet filtering.

How to shut down the internet

• Routing disruptions Every device connected to the internet, whether it’s your computer, smartphone, or any other device, has an IP (internet protocol) address assigned to it.
• An autonomous system is a collection of connected IP networks under the control of a single entity, for instance an internet service provider or big company.
• So, if an autonomous system, like an internet service provider, suddenly withdraws its border gateway protocol routes from the internet, the block of IP addresses they administer disappears from the routing tables.
• As a consequence, customers using IP addresses from that autonomous system can’t connect to the internet.
• Packet filtering To target specific content, governments often use packet filtering – shutting down only parts of the internet.

Violation of rights

• A detailed overview of techniques is provided by Access Now, an NGO defending digital civil rights of people around the world.
• There is wide agreement that internet shutdowns are a violation of fundamental rights such as freedom of expression.