its fine with them as far as i know.
regulating account trades will be more of a problem as sellers will find other ways to sell it whenever they get caught
People have been openly trading accounts for a long time. See https://bitcointalk.org/index.php?board=93.0
One of the main reasons is to attempt ROI on a signature campaign. People buy accounts, enroll in a signature campaign and post to get their money back.
But as more and more people doing that the value of the account decreases, its just supply & demand.
If it continues, then it will push down sig campaign rewards aswell ,not only account value.
Actually its better to sell it fast, because later on it will be valued less.
Its like with keynesian economics, how they make this consumerism economy work, they inflate the money out of your hands, so that you will be forced to shop all day so that you can buy things before the money in your hands evaporate in value.