Thought I would add a few pieces of insight as it caught my interest as well (both the scamming and plat duping).
The person scamming Mark of Shadows was by a character named "Moncy" who still actively sells in the bazaar and auction channel. This was first brought to everyone's attention when he began auctioning Mark of Shadows in auction for 4 krono linking the Vex Thall item, then attempting to trade the statless Mark of Shadows item to people. After he was called out he put Mark of Shadows for sale in trade mode for 99,999pp (the next lowest was 300k at the time) and it was either taken down or bought within 2 days.
As for the plat dupe, there seems to be a pretty clear buying pattern and response to it. On the day Luclin was released, krono prices were at a steady 30k per with slight fluctuation. Two days after Luclin release, every single krono over the course of an afternoon was bought and you saw krono prices sky rocket to 45k. The next days prices diminished, eventually coming down to the high 30s in price and did a small but steady increase over the next 10 days and ended at a steady 40k average price. Yesterday the exact same thing happened that happened 2 days after Luclin launch, every krono in the bazaar was bought out (I would approximate about 150) and prices within 8 hours shot up to 60k as a result of the mass purchases. Today you will see the same effects as last time, krono prices are slowly dropping again down to 53-55k range. I imagine within the next 2 weeks you will see another krono buy bomb and will get a spike up to 75-80k.