Feeds

Gone in 30 minutes: Chinese tweets purged by army of censors

New report claims thousands of censors could be working for Sina Weibo

New hybrid storage solutions

The murky world of online self-censorship in China has come under the spotlight again in a new report which estimates that most post deletions on the Twitter-like Sina Weibo occur within the first 30 minutes of appearing.

The Velocity of Censorship: High-Fidelity Detection of Microblog Post Deletions, was researched by academics at Bowdoin College, Rice University and the University of New Mexico alongside independent researcher Tao Zhu(h/t MIT Technology Review).

Sina claims its service has over 500 million users, but for the purposes of this research the team concentrated on the posts of around 3,500 “sensitive” users with a track record of censorship.

Developing a system “which collects removed posts on targeted users in almost real time”, the researchers found that roughly 12 per cent of posts were deleted over the 15 day monitoring period – which amounts to more than 4,500 every day.

The research included the following observation(PDF):

Our research found that deletions happen most heavily in the first hour after a post has been made. Especially for original posts that are not reposts, most deletions occur within 5-30 minutes, accounting for 25 per cent of the total deletions of such posts. Nearly 90 per cent of the deletions of such posts happen within the first 24 hours of the post.

To enable such speedy censorship, the report claims a mixture of technical and non-technical filtering is used, with potentially thousands of staff employed to eyeball content, as per the following hypothesis:

The deletions happen most heavily for a regular post within 5 to 10 minutes of it being posted. Suppose an efficient worker can read 50 posts per minute, including the reposts and figures included in the posts. Then to read Weibo’s full 70,000 new posts in one minute, 1,400 workers working at the same time would be needed. If these workers only worked in 8 hour shifts, 4,200 workers would then be required.

Proactive keyword filtering blocks certain posts before they have gone live, or holds them for human review, while a range of retroactive mechanisms including backwards keyword and repost searches, public timeline filtering and monitoring of specific censorship-prone individuals were also highlighted in the report.

The research also hypothesises that the censors work “relatively independently, in a distributed fashion”, with activity only really dipping between around 1-7am and again slightly at 7pm – which the report authors claim could be due to the national TV news programme broadcast at that time.

Although the report casts new light on the speed and accuracy of China’s web censors, it doesn’t explain why more isn’t done to block potentially illegal content before it is even posted.

One possible answer came from Sina Weibo manager @geniune_Yu_Yang (正版于洋), who – apparently frustrated by user anger directed at the company’s army of censors - wrote an illuminating post of his own back in January.

He effectively argued that Sina is trying to work around the strict regulations forced upon it by government, by at least letting users see and disseminate their content for a few minutes before it is deleted.

He wrote:

You can see the messages before they are deleted, right? You still have your account functioning, right? You are all experienced netizens, you know that the technology allows us to delete messages in a second. Please think carefully on this.

Now, there is no way of proving whether this manager was engaging in a crafty piece of well-timed PR or if there’s some truth to his claims.

Somewhat ironically, his post too was deleted, which illustrates perfectly the central problem with censorship of this kind: there's no way of telling whether a piece of content is deleted because it was true, or because it wasn't. ®

Providing a secure and efficient Helpdesk

More from The Register

next story
Found inside ISIS terror chap's laptop: CELINE DION tunes
REPORT: Stash of terrorist material found in Syria Dell box
Show us your Five-Eyes SECRETS says Privacy International
Refusal to disclose GCHQ canteen menus and prices triggers Euro Human Rights Court action
Heavy VPN users are probably pirates, says BBC
And ISPs should nab 'em on our behalf
Former Bitcoin Foundation chair pleads guilty to money-laundering charge
Charlie Shrem plea deal could still get him five YEARS in chokey
NORKS ban Wi-Fi and satellite internet at embassies
Crackdown on tardy diplomatic sysadmins providing accidental unfiltered internet access
'Serious flaws in the Vertigan report' says broadband boffin
Report 'fails reality test' , is 'simply wrong' and offers ''convenient' justification for FTTN says Rod Tucker
FAIL.GOV – Government asks Dropbox for accounts that don't exist
Storage locker's transparency report shows rise in government data gobble attempts
prev story

Whitepapers

Providing a secure and efficient Helpdesk
A single remote control platform for user support is be key to providing an efficient helpdesk. Retain full control over the way in which screen and keystroke data is transmitted.
Top 5 reasons to deploy VMware with Tegile
Data demand and the rise of virtualization is challenging IT teams to deliver storage performance, scalability and capacity that can keep up, while maximizing efficiency.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.
Secure remote control for conventional and virtual desktops
Balancing user privacy and privileged access, in accordance with compliance frameworks and legislation. Evaluating any potential remote control choice.