“It would be really difficult for a provider to do that,” he added.
It’s insanely easy for a provider to do that. Any half-reasonable programmer could cook up an update to a provider’s email system to do that in a day or two. Any a half-way decent regular expression library should be able to do it reasonably efficiently as well.
Even easier if a provider is already scraping users’ emails for personal information. (Not sure if Yahoo does that or not).
