Holman Jenkins has a different take on Congress's insiders engaged in insider trading ("Congress's Insider-Trading Non-Scandal"). He writes that, "There are few ways in which a congressman can be more innocently employed than in day trading." But, on the whole, "... congressmen underperform the market for all the same reasons that most active traders do. They buy high, sell low and waste money on trading commissions."
Points granted. They are all just people, like the rest of us. But they are the ones who suggest that they go by a higher standard ("public servants"). They are the ones who are zealous about regulating all of the (other) "greedy" people out there. They are the ones who have the power to tax, subpeona, prosecute, regulate, etc. They are the ones who are always ready and eager to exempt themselves form the laws and regulations they impose on others.
I agree with Jenkins that "insider trading" is a complex idea and there are always over-zealous prosecutions (e.g., Martha Stewart). But I worry about under-zealous (probably no such word) when it comes to the folks who are special in the four ways I just mentioned.