According to 9to5Mac http://www.tipb.com/2011/04/26/att-continuing-crackdown-unofficial-mywi-tethering/?utm_source=twitterfeed&utm_medium=twitter&utm_campaign=Feed%3A+TheIphoneBlog+%28TiPb%3A+iPhone%2C+iPad%2C+iPod%29&utm_content=Twitter AT&T is now pursuing their initial warnings and adding the tethering plans without question. Below is the received text message. Text Message: AT&T Free Msg: Weve noticed youre continuing to enjoy the tethering feature with your smartphone service. Remember, you need a tethering plan ($45/mo, incl. 4GB) to use this feature, so were planning to update your line with the required plan soon. Visit att.com/dataplans or call 888-860-6789.