Leave router on 24/7?

[Compass Rose]

About 6 months ago, I had a Direct TV guy tell me the same thing in that I should leave my internet plugged into the TV turned on all the time however, I don't agree. I just connect the TV to the internet when we need it, which is very rarely.

As for my household, we use the internet service 365 days a year. I would say that I unplug my router and modem at bedtime at least 350 nights a year.

I may be wrong in my thinking however, from my POV, if you aren't needing your internet while you sleep and you leave it on unattended, you could get hacked and you'd never know it.