If the platters inside are undamaged then a hard disk data recovery company COULD probably get the data off.
However if all the electronics and the "fittings" are damaged then it is unlikely the average "man in the street" could get any data off them.
Note there is software that you can run (before taking the PC apart of course) that can write rubbish data all over the disk multiple times that will remove all (most?) traces of any of your data.
DBAN is one such product (free)
http://www.dban.org/