Note: As of December, 2006, the information on this page has been largely invalidated as a result of a presidential "signing statement" affixed to H.R. 6407, the "Postal Accountability and Enhancement Act". Please click here for details on the new state of affairs.
This page is left here primarily for historical interest.
For a number of reasons, people today are becoming increasingly interested in, and concerned about, their privacy and that of their communications. Email security and encryption are becoming increasingly popular, as are electronic firewalls, security systems, and anti-virus and -spyware suites. Whether anyone is trying to, or even wants to, read your email without your permission, there's nothing wrong with security for security's sake. If you're one of the millions of people who doubt the intentions or actions of the United States Government and their relentless quest for neverending domestic surveillance and intelligence-gathering, you are doubtless well-familiar with all the ways of keeping Uncle Sam from snooping in your private communications.
If you haven't completely escaped the clutches of the mundane world, however, the odds are good you send or receive at least a few pieces of physical, or "snail", mail every year. Whether or not one engages in activities that put themself at risk of scrutiny by the government, or even if one takes a more pessimistic view of the government's actions since the passing of the USA PATRIOT Act, examining the privacy of your mail is still an interesting and educational enterprise.
In the parlance of the United States government, the interception, interdiction, and perusal of your mail is known as a "mail cover". It's defined by bureaucrats as "the process by which a nonconsensual record is made of any data appearing on the outside cover of any sealed or unsealed class of mail matter, or by which a record is made of the contents of any unsealed class of mail matter as allowed by law". A mail cover can be initiated for a number of reasons sufficiently broad in scope and vague in wording that it is reasonable and realistic to say that if the government would like to employ a mail cover, they can. Disheartened? You needn't be.
The nice bit is this - they can examine and record the "outside cover" of any mail you get, or send - addresses and such on envelopes and boxes. Under a mail cover, however, they can only open and peruse the contents of "unsealed mail", but not "sealed mail". Sealed versus unsealed has nothing to do with whether you licked the flap of the envelope or taped the box shut - it has only to do with the class of postage it's mailed as. First-class, Priority, and Express mail are "sealed", while second-, third-, and fourth-class, plus parcel- and media-rate mail, are "unsealed". While browsing everyone's mail is a logistical impossibility, merely due to volume, given the current political climate, the general disregard for civil liberties prevalent in the govenment, and the fact that unsealed classes of mail can be opened for any number of quite flimsy reasons (not least of which is the much-abused "National Security"), it is reasonable to say categorically than no reasonable expectation of privacy exists for domestic mail sent at any rate below first-class. There really is nothing to stop the Federal Bureau of Information, or the Department of Homeland Insecurity, from getting a mail cover as a fishing expedition on the feeblest of excuses.
But what about "sealed mail", first-class and Priority Mail packages? Big Brother can peruse the outside of the box or envelope to their heart's content, but with one exception, they can only open this class of mail with a warrant, and while standards have eroded a lot in the past few years, it's still much, much harder to get a warrant than a mail cover. The exception is that certain postal officials only may open "sealed mail" with illegible addresses to attempt to locate a delivery address inside, and they're theoretically prohibited from perusing any included correspondance. Now, for the really paranoid, there's theoretically little to stop the remote possibility of an overzealous law-enforcement officer from getting a mail cover under flimsy pretenses, then "accidentally" obliterating the outside address on an interesting-looking letter or package while examining it's exterior, and then "accidentally" getting a look at the contents when his or her conveniently-suborned postal lackey opens it to try and identify the delivery address, except perhaps making the address as indelible as possible. It would be extremely hard indeed to "accidentally" or "conveniently" deface or obliterate an address written in permenant marker (Sharpie(tm)) or an indelible laundry marker or crayon, for instance.
One remaining exception exists, in that Postal Inspectors only, may inspect packages suspected of containing hazardous, dangerous, or otherwise "unmailable" material. They are, however, required to perform the minimum necessary inspection, which would typically be x-raying or (because I know there's some sort of dumbass reading this with high hopes) having a drug-sniffing dog sniff the unopened package. As the subject of this page is protecting your privacy, not a primer on sending things thru the mail that you aren't supposed to, that's all I have to say about that...
So what's the point of all this? If you're engaged in activities making you likely to attract or have attracted close scrutiny from the jackbooted forces of oppression, or you're just concerned about the privacy and confidentiality of your mail, whether business or personal, making sure that, whenever possible, your incoming and outgoing mail is sent first-class or better, and is indelibly addressed, perhaps in multiple locations.