than they did in 2009. biggest mistake they made is when they refused to come out in support of the demonstrators two years ago. reporter: tomorrow s protests in tehran are being promoted online but we have to see if the internet plays a big role as did it in egypt. gregg: turning to your health, there are new concerns over dangers. americans getting exposed to medical radiation. it can diagnosis patients but too much radiation can increase the risk of cancer. casey stegall is thrive in our l.a. bureau with more. how much is too much? two-thirds of americans have received this type of testing, first of all and this may surprise a lot of people. doctors really do not know the full side effects of this medical radiation thasm the is