could be a problem for wifi captive portals that redirect to 1.1.1.1, but most of them would never route to begin with. However, I believe the real issue is

could be a problem for wifi captive portals that redirect to 1.1.1.1, but most of them would never route to begin with. However, I believe the real issue is that it is a free DNS server, so someone could redirect all domains that do not use ssl pinning.