Securing our nation's Cyber Infrastructure

I was thinking one of the easiest ways to secure any cyber infrastructure would be to take it off the internet and have that system only transmit over private hard line phone lines. Even though this could also easily be hacked, it would take someone here physically in the U.S. to do that by climbing telephone poles and hacking directly into lines like that. By removing systems now tied to the internet away from the internet, it allows companies to function, (especially dams, power generating facilities etc), by being less vulnerable generally speaking. This also could work for banks as well if this was thought out in detail right. Also, I think more and more customers are going to realize like I did that online banking is no longer safe and the banks can no longer protect customers who continue to do online banking or be responsible for what happens to them legally.

Anyway systems can be removed from ANY general worldwide internet Access  will reduce the amount of problems. In some ways it doesn't matter even if there are passwords because there are ways to circumvent almost any password under about 25 characters now. So this way only company employees would have access to   private phone lines through which this private internet would be run for any major U.S. cyber infrastructure company.