Social networks are being slowed down after explosion in Istanbul.

Currently Facebook, Instagram, Twitter, TikTok, YouTube seem to be slowed down.
Reddit, VK and Telegram seem to work fine.

It’s a different blocking mechanism than one used for completely blocked sites (i.e. for Porn sites).

I’ve made some experiments on mobile Turkcell, here’s what I found:

1. Connections are being slowed down, not blocked completely
2. Slow down happens by SNI — so using “allowed” SNI and connecting to Facebook balancers works fine
3. When connecting without SNI, connection is only slowed down if there were connections to that IP with slowed down SNIs, for example:

# 1.1.1.1 is not associated with Facebook, so it’s not slowed down yet
# time curl -qs https://1.1.1.1 >/dev/null
real    0m 0.91s
# now connect to 1.1.1.1 with a slowed down SNI
# time curl -qs https://facebook.com --resolve facebook.com:443:1.1.1.1 >/dev/null
Command exited with non-zero status 60
real    0m 7.75s
# try connecting to 1.1.1.1 without SNI again, and now it’s slowed down
# time curl -qs https://1.1.1.1 >/dev/null
Command exited with non-zero status 92
real    0m 17.77s

After reconnecting to network, this association is reset (so 1.1.1.1 is not slowed down after toggling airplane mode on and off).
I don’t know if it’s because I go to a different instance of filters, or they’re simply always start from clean state.

EDIT: most likely it always starts with a clean state, since same happens for facebook.com’s IP:

# time curl -k https://157.240.238.35
real    0m 0.87s
# time curl https://facebook.com 
real    0m 11.05s
# time curl -k https://157.240.238.35
curl: (92) HTTP/2 stream 1 was not closed cleanly before end of the underlying stream
Command exited with non-zero status 92
real    1m 1.32s

4. it’s a different mechanism from one used for blocked websites — when doing the same as in step 3 with pornhub.com, 1.1.1.1 doesn’t become blocked or slowed down
5. HTTP seems to work fine, and only HTTPS seems to be slowed down — but I’m not sure since I don’t know how to test this one properly

There have been reports on BTK providing official comment, something like this:

At the request of the relevant units, the band narrowing was implemented by the BTK for the social media platforms across the country for the unethical images and terrorist content that emerged after the explosion in Taksim.

I wasn’t able to find a proper source for it, so I won’t be posting any.

Netblocks Report: Social media restricted in Turkey after blast in Taksim, Istanbul - NetBlocks

I see a report now that the throttling of social media has ended. I don’t know exactly when.

https://twitter.com/arzugeybulla/status/1592035768356450304

OONI has some measurements.

They’ve ended sometime after midnight local time, I believe.

Social media and messenger apps like X, YouTube, Telegram, Instagram are inaccessible in Turkey today, the censorship event can be related to the arrest of the mayor of Istanbul (one of the oppositional leaders in the country): Bant genişliği daraltılan platformlar – İfade Özgürlüğü Derneği