Can I LEGALLY have a wifi hotspot/mesh network business using a business class ISP??

[VetTechJess]

I want to start a wifi hotspot mixed with a mesh network. I am hesitant to get started because it requires "borrowing" a broadband internet connection from an ISP. I know that most business level broadband internet access allows for sharing of the internet connection.

My biggest fear is that if I do start offering free internet via mesh networking thru a business class broadband connection, and start to make a ton of money off it thru redirecting of the homepage to my adsense laden blog site, then isn't it somehow a violation of the broadband ISP's Terms of Service? Wouldn't they be losing profits because of me, thus wanting to sue me for monetary damages?

I am not a wealthy person. I have no assets to go up against the big name companies in a huge legal battle. The other broadband ISP would have a right to charge money for their internet connections, just as I would have the right to offer my internet for free.

but how can I legally do that knowing that I would be offering internet access for free using someone else's connection that they would have to pay for??

Thats the main reason why I would want to build my own internet backbone connection.,,,

ANY IDEAS OR ADVICE?!?!