You could also argue that there is NO contractual requirement to turn them off. Hacking is not really a issue with decent security and changing passwords etc.
As to electricity... Well who care's as I'm paying for it.
While I do not use the internet 24/7, It is used by our mobiles via wifi for emails etc. Which is better than using our data allowance.
As others have said leave router on and you should see your line speed go back to what it was before.
This is really a non issue caused by user.
Wats SUP doc.... You using too much.....