Definitely artificial. No question. Not even "good" artificial toning. This stuff is worth no more than melt value.
These have all been doctored in the same manner, it shows in the consistent toning patterns .. Buyer beware....
The sad part is that if the seller had only posted one or two pieces he may have gotten away with it-- also if he had used higher grades.
It can be done in a number of ways.. oven baked is one. And, yes, there is a nice market for premium naturally toned coins-- that are attractive.
sure, they would probably ban you-- unless you were a power seller. Just kidding-- unless there is clear (and I do mean CLEAR) evidence of fraud they do nothing. It is hard enough to get them to pull 1804 silver dollars -- forget about them doing anything about this!