Hacking
Hacking is an activity in The Sims 2: University and The Sims 3 that can be performed on a computer.
The Sims 2
"Grade Hacking" is an action available on college computers in The Sims 2: University after a Sim joins a secret society. While hacking, a Sim's class performance will slowly rise, however there is also a risk of getting caught, and that risk generally increases the longer the Sim hacks. Having higher Logic skill reduces, but does not eliminate, the chance of getting caught. If a Sim is caught hacking grades, the police will come and fine them, their class performance will be lowered to its original level, and the police officer may pull out a repo-izing gun and confiscate the computer. While hacking, the chance of being caught can be seen in the top-right hand corner of the screen. Players should note that this display may be lost if they switch away from the hacking Sim. Notice that when using a public computer in a dorm, the computer won't be confiscated.
The Sims 3
Sims with the Computer Whiz trait or in the Investigator profession can hack in The Sims 3. Depending on the number of times a Sim has hacked before, a set amount of money is put into the household funds every 30 minutes (20 with the Genius trait). However, you have a chance of the police sending a virus to your sim's computer and breaking it down.