It's not a threat at all. All these accounts have something in common. They are all past bot accounts (gold farming) that no longer were in use. There is not a single account that shows any legit game playing or effort having been invested in them. There is no sign of security weakness in Jagex and most of these passwords are beyond the ability to guess hack. The most probable cause to all these accounts being "hacked" is that they were all signed up to some botting site and that is where the account information has come from.
