Every so often I'll notice that a user with an unfamiliar name begins posting good answers and insightful comments about topics that interest me. Most of the time they are new users, but sometimes they show up with reputations in the high 4 digits (or more), and I then wonder why I haven't noticed their rise to prominence.
It then almost always turns out, on further investigation, that it is a known existing user who has simply changed their display name. But the "further investigation" is tedious and time-consuming; it basically involves trawling through old comment threads the mystery user has posted to, hoping to find one where they have been @addressed by their old name.
For example (to pick one example where there seems to be no privacy concerns), Jennifer Dylan had earned quite a bit of respect from me under the name J.D., which it took some effort to transfer to her new display name.
Would it be possible to have people's profile pages list the display names the user has used in (say) the previous 6 months?
There are some imaginable privacy concerns -- particularly when changing from a real name to a pseudonym -- with I think could be addressed in one of two ways:
Allow moderators to remove earlier names from the list when given good cause. The bar for "good cause" doesn't need to be set much higher than "cares enough about it to flag for moderator action", except perhaps (hypothetically) for consistently obnoxious users who keep changing their names to stay ahead of the ill repute they generate.
Implement the "list of previous names" as a feature that automatically adds "Formerly known as _____." to the user's "about me" text when they change their display name. Then users who actively want to make a clean break from their old name could immediately edit that line away afterwards.
In the first case, it might be a good idea not to list name changes by very new users (say, with less than 10 questions and answers).