Russian and Central Asian militants fighting alongside Islamic State (IS), Al-Qaeda, and the Taliban in Syria and Iraq are disappearing from social-networking sites like Odnoklassniki and VKontakte.
Whereas just a few months ago, these networks were abuzz with propaganda and recruitment activity from personal militant accounts and official propaganda pages, many accounts have been banned, gone quiet, or closed.
Where have all the militants gone?
Continual bans -- particularly on VKontakte -- as well as concerns that law enforcement agencies could monitor recruitment efforts likely account for some of the reduction of militant activity.
Some militants may have deleted their own accounts for security reasons.
Another reason for the slowdown in militant activity could be an uptick in deaths.
And there is also evidence that militants are moving over to the new and more secure Telegram messaging service.
Over the past months, IS has shifted at least some of its propaganda and recruitment efforts to the Telegram mobile messaging app.
More recently, Russian-speaking and Central Asian militants from IS-, Taliban-, and Al-Qaeda-affiliated groups have also opened Telegram accounts.
There are at least four official or semiofficial Russian-language IS news accounts on Telegram -- IS News, ShamToday, FuratMedia, and Voenkorr. The IS News account has been advertised on Twitter this week as the official Russian-language IS Telegram group.
The ShamToday account was opened on September 23 and has just 21 members.
FuratMedia has yet to broadcast any messages and appears to be a very new bot. Since the summer, Furat has operated as the de facto official Russian IS propaganda channel, has been repeatedly banned from Facebook and Twitter and has been unable to maintain a presence on VKontakte.
Other militant groups from the former Soviet Union have also recently created platforms on Telegram.
The Uzbek group Tawhid wal-Jihod, which joined Al-Qaeda's Syrian affiliate, has a Telegram group that allows it to broadcast to subscribers and the Taliban-aligned Imam Bukhari Jamaat runs a personal account.
There are several reasons why Russian and Central Asian militants likely prefer Telegram for recruitment and propaganda.
The most important feature is security. Telegram offers "secret chats" that use end-to-end encryption -- so recruiters can chat securely to would-be recruits or donors.
Abu Rofik, a publicist and recruiter for Syria's Al-Qaeda affiliate, the Al-Nusra Front, instructed wannabe recruits to contact him privately via his Telegram account this week.
For militants whose propaganda efforts have been hampered by frequent bans from VKontakte, Telegram is also attractive. The messaging service says it does not process any takedown requests relating to Telegram chats and group chats, as these are "the private territory of their respective participants."
So recruiters like Abu Rofik who operate private accounts will not be banned, although Telegram will consider requests to ban public bots that receive complaints including "terrorist (e.g. ISIS-related) bots."
The noticeable slowdown in militant activity on VKontakte and Odnoklassniki could, at least in part, be a result of an increased number of deaths that has built up over recent months.
The slowdown has been particularly noticeable among Tajik militants, according to RFE/RL's Tajik Service, which noted this week that Tajik activity on social networks has all but completely subsided.
The Tajik authorities believe that the silence is a result of a large number of deaths among Tajik militants, as well as an uptick in militants who have become disillusioned and tried to return home, according to a law enforcement source.
The source, who spoke to RFE/RL's Tajik Service on condition of anonymity, said 300 Tajiks had been killed in Syria and Iraq and only around 200 remained. The source added that more than 20 parents of individuals who went to Syria had asked for help returning their children, who are on the Turkish border.
It is not possible to independently verify these figures, though the combined total of 500 is the official figure given by Tajikistan's Interior Ministry in June for the number of Tajiks fighting in IS.
IS does not publish casualty figures for its militants, making it impossible to know how many fighters of each nationality have died. But there have been signs of an increased casualty rate among IS militants over the past months, including of Russian-speaking and Central Asian fighters in IS's offensive at Baiji in Iraq.
"Obituaries" posted on social media over the summer and early fall by Russian-speaking militants indicated that large numbers of IS recruits had been sent to Baiji as "cannon fodder."
Non-IS sources in Syria claimed that the Baiji offensive was led by IS's ethnic Chechen commander, Umar al-Shishani, who is noted for sending waves of inexperienced fighters to their deaths.
Iraq claimed to have pushed IS out of Baiji last month, and said its forces had found 19 mass graves containing around 365 IS bodies, though it was unclear how long the bodies had been buried there.
Some IS militants may have removed their VKontakte or Odnoklassniki accounts deliberately, fearing that if they give away their locations or phone numbers they could be targeted in Russian or U.S.-led air strikes.
IS commanders -- including Umar al-Shishani, who has not been photographed for months -- may have issued orders insisting that militants remove their accounts.
In April, IS militants from the Chechen-led Al-Aqsa Brigade accidentally gave away the location of what appeared to be a training camp in Muqla Kabir in Raqqa Province by forgetting to turn off location services on a photograph posted to VKontakte.