Is it this bad in Europe and Asia? or just in the US? Almost every day we hear banks doing this, banks doing that - most of it is unethical, and many of it probably illegal, yet nothing seems to be happening to them. This is depressing.
What can government/regulators do? If they respond harshly and abruptly, they are criticized as being too heavy handed, and enemies of capitalism. If they respond slowly and deliberately, they are called slow and ineffective.
What can they do, indeed?
If firms chose not to trade, when they otherwise would have done (which seems to be the case here), based on insider information, that is nigh on impossible to prove.