That said, I think using the "mens rea" argument associated with implicit guilt is how dangerous precedents are born.
I'm specifically concerned with this excerpt from from Sarbanes-Oxley act which is being misappropriated by prosecutors:
>Whoever knowingly alters, destroys, mutilates, conceals, covers up, falsifies, or makes a false entry in any record, document, or tangible object with the intent to impede, obstruct, or influence the investigation or proper administration of any matter within the jurisdiction of any department or agency of the United States or any case filed under title 11, or in relation to or contemplation of any such matter or case, shall be fined under this title, imprisoned not more than 20 years, or both.
Deleting videos and attempting to reformat a computer after the Boston marathon are done knowingly. Clearing one's cache/browser history is in many situations an automatic action, and it's troubling to find it lumped in with pre-meditated action.
I see justification for 3 counts of obstruction, not 4. The 4th looks like an attempt to set the modus operandi of the courts in dealing with our web/online history, and I don't think anything which draws attention to that is necessarily a bad thing...