Hi, I was wondering if anyone could let me know whether a large amount of network activity could mean my Mac has been hacked. Yesterday I opened activity monitor and noticed around 440mb of data had been received, I had been watching a couple of videos on youtube but this only came to about 200mb, so there's around another 200+mb that I can't explain. Does anyone know what this could be? Is there anyway to confirm that I've been hacked? I have been monitoring today and it seems ok. I hope I'm being paranoid but this is causing me some anxiety.