-for- = Format; 2k = 2,000 pictures 4GB Card

I also have a D70S that had some problems.  Nonetheless it appeared that your D70S started formatting CF card, probably because you touched the two buttons simultaneously?  You have to push those two buttons the second time to start formatting.  However if you removed your battery in the middle the format the process is interrupted.  That may explain why old pictures are not completely erased.