[kibwen]

I'm explicitly disregarding government websites here, since the government has a legitimate reason to care about my full name (and gets to define what a "legal" name means), and also 99% of the websites that I sign up for are unrelated to the government. There's no reason for a social network to report the names of all its users to a government agency automatically, and I'm skeptical that even my bank would have such a requirement.

[smallnamespace]

I don't mean reporting all the names, but for example if you ever transmit payments there is a KYC process, and if you are a bank you must report any suspicious money laundering activity.

At the end of the day there are cultural conventions around names, and various agencies use them. I don't see why software should be explicitly culturally neutral, unless your audience is explicitly a global one (and even then, I think localization is preferable to just sticking names into a single field).

[Thrillington]

There is significant engineering cost to implement localization correctly. If you're a bank or in another market where you interact with a government, then you must bear those costs. If not, why not just use an opaque string and spend your engineering dollars on your actual product?