B. Suppose instead that Miller had written a routine to constantly change his assigned IP address to other addresses used by his ISP. If the SLS intrusion system determined what Miller was doing and then added the entire range of ISP addresses to the banned list, thus stopping any user of the ISP from connecting to the SLS network, would SLS’s action be ethical?

It wouldn't be legal practice of SLS’

Explanation:

The Internet service address is the address of the internet where we getting the address of the internet sometimes it is known as the computer address of the host machine.  

Since the miller has changed the Ip address continuously in a constant manner also the other address which is giving by the internet service provider  The transfer of IP address, Miller will be able to receive their network. That sort of practice is not legal of SLS.

a software engineer i believe