I have recently being monitoring my network traffic with activity monitor. I have noticed that the 'Data sent' section seems quite high (when I looked earlier it was at 1GB received and 500mb sent, I'm sure the data sent is usually much lower), especially when watching Youtube videos. When I'm on my PC and monitor the 'data sent' activity in Task Manager it is much lower, even when I'm browsing the same webpages/watching the same Youtube videos. Does anyone have any ideas as to why this is. I am hoping I am being paranoid but does this sound like a security issue?