As you probably know, e-mailed information often ends up in databases that can be used against us by government agents, corporate spies or even acquaintances out to avenge real or imagined injuries. (I spent two years unsuccessfully trying to salvage online materials that were stolen or destroyed by a malicious hacker who’d pretended to be something else.)

And it’s just as easy for online criminals to destroy evidence of their crimes as it is for them to harass and steal from non-criminals. This is a point Matt Taibbi underscores in his most recent piece on Wall Street corruption, a story the mainstream media doesn’t want to tell:

Imagine a world in which a man who is repeatedly investigated for a string of serious crimes, but never prosecuted, has his slate wiped clean every time the cops fail to make a case. No more Lifetime channel specials where the murderer is unveiled after police stumble upon past intrigues in some old file – “Hey, chief, didja know this guy had two wives die falling down the stairs?” No more burglary sprees cracked when some sharp cop sees the same name pop up in one too many witness statements. This is a different world, one far friendlier to lawbreakers, where even the suspicion of wrongdoing gets wiped from the record.

That, it now appears, is exactly how the Securities and Exchange Commission has been treating the Wall Street criminals who cratered the global economy a few years back. For the past two decades, according to a whistle-blower at the SEC who recently came forward to Congress, the agency has been systematically destroying records of its preliminary investigations once they are closed. By whitewashing the files of some of the nation’s worst financial criminals, the SEC has kept an entire generation of federal investigators in the dark about past inquiries into insider trading, fraud and market manipulation against companies like Goldman Sachs, Deutsche Bank and AIG. With a few strokes of the keyboard, the evidence gathered during thousands of investigations – “18,000 … including Madoff,” as one high-ranking SEC official put it during a panicked meeting about the destruction – has apparently disappeared forever into the wormhole of history.