I go onto Activity monitor, just out of curiosity, and find Finder using up about 50% of my CPU! kernel_task was also running high at about 20%. I wasn't doing a thing in Finder, and the only major thing I did was convert an iMovie Project to MPEG-4 format, but the job had finished about 10 minutes before I checked Finder out. I decided to relaunch Finder, as I wasn't doing anything on it. Everything seemed alright after this. But, I scrolled down and found rcd was in a hang, so I quitted it (as I already had an appetite for destruction ), thinking it would relaunch, but it still hasn't, and I am kinda scared... I decided to keep AM open, if anything funny happens. Then, WindowServer pops up every now and then, using at least 80% of my precious CPU power! What is wrong with my Mac? All of these processes were owned by User, not System, I think. I know I shouldn't jump to conclusions, but is someone hacking my Mac? Does this sort of thing happen on everyone else's machine?