Would you reg all (main) country extensions in order to own the brand if they were still available? domain is a pronounceable & only premium letter containing LLLLL Please vote
I would say for most people the answer is no. There is no need to protect your brand like that unless it's truly a big brand name. If we were talking about a major company that could easily afford to register all extensions for 5-10yrs at a time, then it would be a good idea. For the normal person with a small business, it's not necessary.
I see no point in doing that unless your brand is widely known and widely used. In such cases most of the country DNS organizations will also ensure it stays in the hands of the legitimate owner and most of the DNS TOS prevent brand theft.