MacBook Pro early 2011/OSX 10.7.4
This has also happened to me but I never used the Motion app. My keychain folder bloated to 269 Gb. Applecare told me to delete the Keychain folder (i have copied any login passwords that I need). It looks like it's going to take a couple of hours just to move the folder to the trash. They didn't tell me to move those two files to the desktop as per Linc's instructions above. They said restart the computer after moving the folder to trash and say yes to the create new keychain messages. Then delete the trash.
I have been getting that infuriating password authorisation thing whenever I go to put anything in the trash, and constant requests to allow the keychain when web browsing for months. I searched online but could find nothing useful on resolving those problems so I just put up with it until I realised I was nearly out of HD space.
My question: I can see from console there has been weird stuff going on since my HD was replaced in May by an Apple Authorised Service Provider under my AppleCare Protection Plan. Is there any way to track back using Activity Monitor/console what could have started this? How should I monitor (apart from disk space reducing again) if the root cause of the problem has been licked or is it likely to recur?
I notice several other threads implying Time Machine local backups can cause issues with hard disk space disappearing. I have never had Time machine on although the AASP could maybe have temporarily switched it on when doing the repair - how can I rule that out as the cause? It is off at present.
The first symptom was problems with Google accounts requiring constant authorisation. There is activity on Google forums indicating an issue there which appears unresolved. I prefer Chrome as my browser and I use Gmail extensively but I s'pose I'd sacrifice Chrome though not Gmail if I had to.
Many thanks for any assistance!
Imogen