These answers suffer from a company support representative accepting "a long string of letters" as an answer, which they often do.
Much better to use a 'plausible' answer like "Fielder" or "Pitt" or any random real last name.
Hyphenate it for more entropy - eg: Fielder-Pitt.
You can make it mildly more complex by hyphenating. For example “Moss Coane”.
Sounds plausible enough, but clearly a fake.
I feel so bad for all the people who have the same surnames as their unmarried mothers and don't think this through. I don't know how big that chunk of humanity is, but I feel for them.