The virtual private network provider Golden Frog wrote on its blog that the controls have hit a wide swath of VPN services. Another provider, Astrill, informed its users that the controls have started hitting iPhone access to services such as Gmail this year.
The Chinese government blocks thousands of websites to prevent what it deems politically sensitive information from reaching Chinese users. Many foreigners in China as well as millions of Chinese depend on VPNs to connect to servers outside the country and access blocked information.