Service blocking

Starting from 27th October 2020 – on the eve of Tanzania’s 2020 general election – OONI measurements started to show the blocking of social media platforms in Tanzania.

Specifically, OONI data collected from several networks in Tanzania shows that the testing of WhatsApp presented anomalies between 27th October 2020 to 10th November 2020, suggesting WhatsApp blocking in the country. 

Chart: Blocking of WhatsApp in Tanzania between 27th October 2020 to 10th November 2020 (source: OONI MAT).

In many cases, we see that attempts to connect to WhatsApp Web (web.whatsapp.com) and to WhatsApp’s registration service fail, resulting in generic timeout errors. Yet, TCP connections to the tested endpoints of WhatsApp’s mobile app are often successful. Nonetheless, the failed attempts to WhatsApp Web and to WhatsApp’s registration service suggest that access to both WhatsApp Web and to WhatsApp’s mobile app was most likely blocked in Tanzania.

This is further suggested by the following (main) factors:

• We consistently see the testing of WhatsApp failing in the same ways on the same networks (in multiple measurements);

It therefore seems highly probable that access to WhatsApp was in fact blocked (on multiple networks) in Tanzania amid their 2020 general election. 

Similarly, OONI data collected from several networks in Tanzania shows that the testing of Facebook Messenger presented anomalies between 27th October 2020 to 6th November 2020.

Chart: Blocking of Facebook Messenger in Tanzania between 27th October 2020 to 6th November 2020 (source: OONI MAT).

OONI data suggests that access to Facebook Messenger was blocked in different ways on different networks. For example, some measurements from MIC Tanzania (AS37035) show that TCP connections to Facebook’s endpoints were successful, but DNS lookups did not resolve to Facebook IP addresses. On Airtel (AS37133), we see that DNS lookups are resolved to Facebook IP addresses, but a few TCP connections to Facebook endpoints failed. Similarly, on Viettel (AS327885) we see that a few TCP connections to Facebook endpoints failed (but the DNS lookups were successful).

Similarly to the testing of WhatsApp, we observe a consistent pattern where the testing of Facebook Messenger consistently presented anomalies on multiple networks in Tanzania from 27th October 2020 onwards, while previous measurements (collected over the last months) show that the app used to be reachable. This (along with the fact that many locals in Tanzania reported difficulties using Facebook over the past day) therefore provides a strong signal that access to Facebook Messenger was interfered with amid Tanzania’s 2020 general election.

In addition to social media apps, Internet Service Providers (ISPs) in Tanzania appear to have likely blocked access to several social media websites as well, as illustrated below.

Chart: Blocking of social media websites in Tanzania from 27th October 2020 onwards (source: OONI MAT).

From the above chart (which aggregates OONI measurement coverage from multiple networks in Tanzania), we can see that twitter.com, www.facebook.com, www.instagram.com, www.tiktok.com, and www.youtube.com presented a relatively large volume of anomalies, primarily between 27th October 2020 to 2nd November 2020. The overall limited measurement volume (particularly in previous dates) presents a limitation to the findings, but the fact that they all presented anomalies during the same date range provides a signal of blocking. 

Learn more through OONI’s research report.