Actually, there is a risk, albeit very low, that you could get in trouble. First, you do have to switch your laptop on upon request, at least in some countries:
The government guidelines say passengers carrying devices which they cannot switch on "face not being allowed to bring the device onto the aircraft". Passengers would then have to choose between charging the device if possible, leaving it behind (see below) or not getting on their flight.
You may have get away by saying "I lost my charger" if the security officer is kind enough (and provided the charger isn't right there in the bag). But there is no guarantee this will work as the airport security is within their rights to confiscate your laptop in that case.
Second, illegal software/movies have to be discovered on your laptop. In practice, your laptop rarely will be checked at all, unless you draw attention for other reasons (e.g. look like a guy on a red-corner notice). Of course, you may still get in trouble if you have a media player open with a movie watermarked with "not for distribution" labels, or a torrent client running. If a movie or a game on your laptop look reasonably genuine, it's inconceivable for the airport security to verify its origins.
So I wouldn't worry about it so much, but reasonable precautions wouldn't hurt. Keeping your "x-files" on an encrypted drive is a bit of an overkill, but it's not that unreasonable, considering how little effort it requires.