The point of Levine's post is that for the markets to work, there have to be traders trading at an advantage. The point of insider trading laws isn't to level the playing field --- that's exactly what you don't want. It's to eliminate a class of agency problems.
We can (probably should) want to deter credit card companies from trading on data mining payment data without believing that insider trading laws are the right vehicle to do that with. Privacy regulations and mandatory confidentiality agreements could set up an effective civil deterrent, rather than sporadic and incoherent SEC and criminal investigations.