Q: My curser moves by itself, as thought somebody has hacked my computer (I'm guessing through file sharing), how do I stop this?

Open System Preferences / Sharing and make sure EVERYTHING is unchecked.

Else read:  http://support.apple.com/kb/TS1449

There are several possible causes for this issue. Take each of the following steps until it's resolved.

1. Follow the instructions in this support article.

2. Boot in safe mode and test, preferably without launching any third-party applications. If you don't have the problem in safe mode, but it comes back when you reboot as usual, stop here and post your results. If you can't boot in safe mode, do the same. If you booted in safe mode and there was no change, go on to the next step.

3. Reset the System Management Controller.

4. If you're using a Bluetooth trackpad, investigate potential sources of interference, including USB 3 devices.

5. A swollen battery in a MacBook Pro or Air can impinge on the trackpad from below and cause erratic behavior. If you have trouble clicking the trackpad, this is likely the reason. The battery must be replaced.

6. There's a report that a (possibly defective) Thunderbolt Ethernet adapter can cause the built in trackpad of a MacBook to  behave erratically. If you're using such an adapter, disconnect it and test.

7. There's also a report of erratic cursor movements caused by an external display that was connected but not turned on.

8. If none of the above applies, or if you have another reason to think your computer is being remotely controlled, remove it from the network by turning off Wi-Fi (or your Wi-Fi access point), disconnecting from a Bluetooth network link, and unplugging the Ethernet cable or USB modem, whichever is applicable. If the cursor movements stop at once, you should suspect an intrusion.

9. Make a "Genius" appointment at an Apple Store to have the machine tested.

I experienced this issue aswell, i discovered it was my tackpad that was broken.

To see if this is your problem, get a mouse, plug it in and go to:

     System Preferences> Accessibility> Mouse & Trackpad

               Then check the box that says "Ignore built-in trackpad when mouse or wireless trackpad is present"

If your cursor stops moving, then youre trackpad is broken and youre going to need to get it replaced

There was a similar thread the other day, with a cute ending.

Another community member was also experiencing the nefarious jumping cursor syndrome. Every time he tried to use the Mac at home, the torment would commence.

Turns out the missus had given him a Magic Mouse as a gift. Like some hubbies are prone to do, he made a big fuss about it, did the Bluetooth pairing and all. And promptly forgot about it. But the little toddler didn't so he snuck in and flinched the ignored mouse. Then the little rugrat proceeded to amuse himself by watching daddy squirm every time he got near the Mac.

Took us the better part of two days to figure it out.