The above posts were all made by China Foreign Teachers Union (CFTU), which claims to be an independent union in China, run by expats. Such a union would be illegal under Chinese law. It is more likely a Chinese front to collect the names of teachers in China.
They are banned from most expat sites in China, so have made up a series of Wordpress and Blogger sites, such as China Scam Patrol and China Scam Busters, to give themselves false credibility.
They use hundreds of fake identities to spam internet forums, to give the appearance of a lot of support. They also use these fake identities to attack expat sites that have exposed them in the past, such as China Daily Mail, and to make personal attacks on individuals who have refused to assist them in their plans to extort teachers, recruiters and schools.
You can read about CFTU at http://chinadailymail.com/2013/03/25/china-foreign-teachers-union-could-be-another-chinese-scam/