NO, it is not safe, while your computer remains on, and there is no activity going on, viruses appear on your computer, even fi your on wow, a website or a game, a virus will apear.
Unless you want to risk your compute rbeing bombed by viruses then yes leave on mate. IF you don't want to die from a virus's exploading your computer.
BTW think about the electricity bill please.... Thinking about how much money your using?.... Think about the enviroment please... Think if i leave this on, how many animals/enviroment must die for your own pleasure? Electricity comes from our fossile fuels, by leaving your computer on your using our fossile supply, your gettting a carbon foot print why destroy the world all because you want to have a server up?
If anybody thinks im on about rubbish then fine. But this is happening maybe not now or next week but it is happening...
THINK it may save your life and the enviroment.
How do i know? - I left my computer on hor 12 hours, i had 15 trojans, 45 tracking cookies, 5 spyware, 9 key loggers.
Some may say WTF?!?!?!
That was my punishment for leaving my computer on so... Unless you want that happening to your computer and having your anti-virus attacking your computer thinking it's a virus then please leave it on.
Thank you for your time.
Tried it.... never again.... Save the enviroment forever!