The Open Observatory of Network Interference (OONI) is a free software project under The Tor Project which aims to empower decentralized efforts in increasing transparency of internet censorship around the world.
We develop free and open source software, called ooniprobe, that you can run to examine the following:
Blocking of websites;
Blocking of instant messaging apps (such as WhatsApp and Facebook Messenger);
Blocking of censorship circumvention tools (such as Tor);
Presence of systems ("middleboxes") in your network that might be responsible for censorship and/or surveillance;
Speed and performance of your network.
By running ooniprobe, you can collect data that can serve as evidence of internet censorship since it shows how, when, where, and by whom it is implemented.