he who controls the route knows everything

there are plenty of hack tools to do that, he/she doesn't have to be an expert to hack into your system. As long as he/she has time to do that, he can do that w/o any technical barrier.

he can easily get your mac address, and even pretend to be the server you are accessing: e.g. he can pretend he is tdameritrade , if that's where you login a lot for your stock, all he need is run a software and get your password to your bank or stock ... he only need to succeed once, think about it...

don't take chance if you are using network handling your money etc.