"What do the two above have in common?" Game

Simple, find something the two above posters have in common, be it something obvious like their join dates or something obscure that one typically wouldn't think of when seeing those two members.

Example:
P1: Both joined in Jan 2011!
P2: ^^ & ^ welcomed me on my first day here!
P3: Both ended their sentences with "!".

Let's get started~

^^ & ^ are both nonexistent.