This is most definitely a botched job of the OP wipe for inactive and new accounts. They've done it and forgot to put in a filter to skip active accounts and its just wiped everyone's OPs that where in the warehouse in large stacks.
I also have reasons to believe the injections are still not fixed, or they haven't found the injector(s). Pain 7, swift both dropped 10op in price (again) over night, the same night we could all find over 4 pages of Op hammers on the AH, when there would only be 1 on the AH at a time.
Please fix the game, hire more GMs and fix your attitudes because staff reviews as well as player reviews are awful.