For expatriates living in China, the list of gripes that come with facing everyday life is long. Generally among those complaints sit Internet speed, pollution and food safety. But in recent weeks concern about the Internet has taken primacy as access to websites - especially foreign websites and virtual private networks, or VPNs, which allow users to circumvent Chinese Internet filters - has deteriorated.

　　The likely reason is the weeklong 18th Party Congress, a highly scripted but nevertheless critical political event scheduled to culminate with the unveiling of Communist Party's next generation of leaders.

　　Chinese authorities routinely move to exert more control over the Internet around big meetings and politically sensitive dates, including by disrupting traffic to foreign websites outside the country's censorship system, commonly referred to as the Great Firewall. But a number of users have complained of unusually frequent disruptions in the run-up to the 18th Party Congress, with some saying they had all but given up trying to use Google's search engine and email service.

　　Data from CloudFlare Inc., a company that provides web performance and security services for hundreds of thousands of websites, confirms that Internet users inside China are not just imagining things. CloudFlare Chief Executive Matthew Prince said the company's engineers and consumers have reported increased difficulties with traffic out of China beginning at the end of August.

　　Mr. Prince added that the blocks didn't appear to fit any specific pattern, saying that both foreign sites and domestic Chinese sites experienced blockage problems.

　　Foreigners and a savvy minority of Chinese Internet users have typically gotten around blocks of Western sites like Facebook and Youtube with VPNs, which form an encrypted link to a server outside of the country, thereby directing traffic around China's Internet filters. But in recent weeks VPNs as well have been targeted, with two separate VPN companies telling China Real Time that they have noticed an uptick in blockages and interferences.

　　A spokesman for Witopia said the recent disruption is 'one of the most severe' the company had ever seen.

　　'We've been in this business for almost eight years and have had customers in China since the beginning. The Chinese government definitely reminds us now and again that they ultimately control their part of the Internet, and disruptions definitely increase surrounding political events,' he added.