Lately Chess.com has been overloading and having all kinds of issues, the site admins have been saying it’s due to a recent big influx of new members. This is horrible because if you are having some intense chess games and all a sudden the site dies you have either lost the game or it just disappeared. Now I can tell you what is most likely happening and I believe it to be user account bots being created. A typical characteristic of a user bot is friend requests or spam, I have been getting multiple friend requests all at once which should never happen since I am mostly quiet on that site and typically deny friend requests.
This could also explain why the influx of new “members out of the blue”. Of course this is just my theory.