Nothing goes unobserved in these digital days... I suspect that Yahoo! archives chat messages typed in the public forum, though I'm not sure about personal messages - there could be a law about privacy in America that I'm not familiar with. However, for things like emails, companies tend to archive the past few month's worth - ISPs are obliged to do things like this in case there's an investigation launched into one of its users - it has to supply information like previous emails, dates logged on, sites visited etc... Usually nobody ever sees any of this. You also have to bear in mind one of the most well-known-about secrets in the world, Echelon. This is (at least) one huge computer system, monitoring ALL electronic conversation world-wide, run in tandem by the British and American intelligence departments. All emails, telephone conversations, text messages are monitored and scanned for a long list of keywords, plus context-sensitive text, and if more than x amount appear in the same email a human operator is flagged to review the message. There's many army listening posts in countries both at home and abroad which aid Echelon in monitoring all communication - there's one army base quite near me that is used solely to monitor transmissions. So, in THAT respect, nothing is sacred any more - not to your government. ;) But yes, generally on the Internet most text chat is archived at least, some larger chat services have a selection of popular rooms (especially those frequented by younger people) which are monitored by human 'moderators'. But when it comes to private one-on-one messaging, it's usually private in the sense that nobody will read it unless something like a court of law or a police force demands all information about an Internet user - in which case all services and communications that they've made would have to be dredged up. Of course, your country's privacy laws have to be taken into consideration as well.