It is a problem, when the camera is focused on the sun for extended periods of time. The heat concentration on the sensor can damage the IR and or Beyer filter, kill individual pixels or even crack the sensor outright.
Also, be extremely careful with DSLRs, the sensor will be fine, but your eye will not.
I had a cousin of mine entirely convinced I was a wizard by predicting one of them. He was five at the time, but his parents sure couldn’t tell him how I did that :D