This paper addresses the questions of whether and, if so, how and to what extent the Internet brings about homogenisation of local cultures in the world. It examines a particular case, that of Thai culture, through an investigation and interpretation of a Usenet newsgroup, soc.culture.thai. Two threads of discussion in the newsgroup are selected. One deals with criticisms of the Thai government and political leaders, and the other focuses on whether the Thai language should be a medium, or perhaps the only medium, of communication in the newsgroup. It is found that, instead of erasing local cultural boundaries, creating a worldwide monolithic culture, the Internet reduplicates the existing cultural boundaries. What the Internet does, on the contrary, is to create an umbrella cosmopolitan culture which is necessary for communication among people from disparate cultures. That culture, however, is devoid of ‘thick’ backgrounds, in Michael Walzer's sense.