Duplicate Rewards for Computer Hacking.
It is possible to duplicate the rewards (XP, credits, and stop/nuke items) for hacking a computer. Just save before hacking a computer and while you are on the "access granted" screen reload your save (do not press the "ok" button) and hack it again. This can be repeated as many times as you want per computer though failing or aborting a hack will reset the stacked up bonuses.