advanced than in any other country in the world. The governmental authorities not only block website content but also monitor the Internet access of individuals; such measures have attracted the derisive nickname "The Great Firewall of China." However, there are some methods of circumventing the censorship by using proxy servers outside the firewall. Users may circumvent all of the censorship and monitoring of the Great Firewall if they have a secure VPN or SSH connection method to a computer outside mainland China. Disruptions of VPN services have been reported and many of the free or popular services are now blocked. On 29 July 2017, Apple complied with an order from the Chinese government to remove all VPN apps from its App Store that were not pre-approved by the government. Different methods are used to block certain websites or pages including DNS poisoning, blocking access to IPs, analyzing and filtering URLs, inspecting filter packets and resetting connections. Memes The Baidu 10 Mythical Creatures, initially a humorous hoax, became a popular and widespread internet meme in China. These ten hoaxes reportedly originated in response to increasing online censorship and have become an icon of Chinese internet users' resistance to it. The State Administration of Press, Publication, Radio, Film and Television issued a directive on 30 March 2009 to highlight 31 categories of content prohibited online, including violence, pornography and content which may "incite ethnic discrimination or undermine social stability". Many Chinese internet users believe the instruction follows the official embarrassment over the "Grass Mud Horse" and the "River Crab". Industry observers believe that the move was designed to stop the spread of parodies or other comments on politically sensitive issues in the runup to the anniversary of the 4 June Tiananmen Square protests. Cyber attacks In the second quarter of 2014, China was by far the main country of origin of cyber attacks, with 43% of the worldwide total. Internet advertising market The size of China's online advertising market was RMB 3.3 billion in the third quarter 2008, up 19.1% compared with the previous quarter. Tencent, Baidu.com Inc, Sina Corp remain the Top 3 in terms of market share. Keyword advertising market size reached RMB 1.46 billion, accounting for 43.8% of the total Internet advertising market with a quarter-on-quarter growth rate of 19.3%, while that of the online advertising site amounted to RMB 1.70 billion, accounting for 50.7% of the total, up