Semi anonymise last name by keeping only first letter

I like to keep first name, but reduce last name to the first letter only. We keep a sense of "real" user while not divulging their identity.

For instance,
- Jean-Baptiste Théard => Jean-Bapttste T.
- Georges Bush Jr => Georges B. Jr
(I appreciate it's not an easy task across all languages but it doesn't has to be perfect)

Also, I would hate my user to be indexed by Google given the field we operate in.