Solar storms can indeed cause damage. They can damage satellites (check out the white streaks on these images - these are from a solar storm :
http://sohowww.nascom.nas...0th/multisun_sm.mpg) or sometimes even cause damage to power lines on Earth (
http://en.wikipedia.org/w..._geomagnetic_storm). Astronauts in space are at significant risk if they are exposed to solar radiation in too high a dose. Because they are above the shielding of the Earth's magnetic field, they don't have the everyday protection you and I have. In the case of a solar storm, they are ordered back into their vehicle and into protective chambers to minimize any radiation dose they may be exposed to. You may not know this but the astronauts on Apollo 16 and 17 were very lucky. Between these two missions there was a large solar storm produced the most amount of protons in a decade - http://curator.jsc.nasa.gov/lunar/images/intro_img_8.jpg . If there had been astronauts on their way to/from the moon at the time, they almost certainly would have died. That is why is it so important that we continue to monitor the Sun and run predictions of if and when a coronal mass ejection will impact the Earth.