It was probably from the contest that asked Insiders to review hotels that ran in June Help us congratulate the Review your Stay Sweepstakes Winners. There were 50 runner-up prizes of 1000 MR points. Not sure if that is where they came from, but that's my best guess.
Consider yourself luck Thor, they deducted 5,000 points due to "Insider Pain in the Neck"!!! Just kidding, glad someone got some points off a promo.