At his weekly audience the Pope will be use a question-and-answer format for his first Twitter session, focusing on answering questions about faith in 140 characters.
In the question-and-answer session which followed, he faced a string of hostile questions about his stance on the strike by 300, 000 teachers and civil servants in June.
Administration officials will spend Wednesday taking questions on the State of the Union in a day-long Office Hours marathon, an online question andanswersession through Twitter.