Twitter and blogs have in the recent years become a platform for spreading information heard at conferences. Short notes (maximal 140 characters for tweets) tell those of use who were not present at the conference what people talked about. I find this a fantastic way to keep updated at what is going on at the forefronts of science, especially as I can’t attend all conferences of interest. In return, I tend to contribute on twitter myself when I am at a meeting. also, as a principle, all of my talks are tweetable and I put my slides online for all to enjoy (unless a collaborator rather not have me do that).
However, some speakers do not want the content of their talk to be spread in this way. Some conferences have policies explicitly allowing opt-out or opt-in statements by speakers. For example, the picture shows the ‘No reporting of any kind allowed for this content’ symbol at the AGBT conference I am currently attending.