Postal mail and Courier services
"Inform the queen!" said Athos; "and how? Have we relations with the court? Could we send anyone to Paris without its being known in the camp? From here to Paris it is a hundred and forty leagues; before our letter was at Angers we should be in a dungeon."
"As to remitting a letter with safety to her Majesty," said Aramis, coloring, "I will take that upon myself. I know a clever person at Tours--"
Aramis stopped on seeing Athos smile.
"Well, do you not adopt this means, Athos?" said d'Artagnan.
"I do not reject it altogether," said Athos; "but I wish to remind Aramis that he cannot quit the camp, and that nobody but one of ourselves is trustworthy; that two hours after the messenger has set out, all the Capuchins, all the police, all the black caps of the cardinal, will know your
letter by heart, and you and your clever person will be arrested."
Some national Post Office services have literally hundreds of years of experience of intercepting letters on behalf of the state or the police etc. For targeted investigations, they have the skills and technology to copy a letter in a sealed envelope, or to make a good copy of a sealed envelope which they have had to destroy when opening it..
It is impractical to intercept lots of postal mail, a much more difficult task than intercepting emails or phone calls, so these powers are reserved for serious cases, such as drug smugglers, terrorists and, unfortunately, Government whistleblowers.
In the United Kingdom, this Postal Communications Interception is covered by the "Regulation of Investigatory Powers Act 2000 section 19 Offence for unauthorised disclosures , with a penalty of up to 2 years in prison for "tipping off" anyone about the existence of or details of an interception warrant (which needs to be rubber stamped by the Home Secretary or a Home Office official), just like phone or email content tapping.
In the United Kingdom, Postal Communications Providers are required, by law, to:
Statutory Instrument 2002 No. 1931
Part I: Interception Capability for Public Postal Services
1. To ensure the interception and temporary retention of postal items destined for addresses in the United Kingdom for provision to the person on whose application the interception warrant was issued.
2. To provide for the interception and retention of postal items sent by identified persons where the carrier keeps records of who sent which item in the course of their normal business.
3. To maintain a system of opening, copying and resealing of any postal item carried for less than £1.
4. To comply with the obligations set out in paragraphs 1 to 3 above in such a manner that the chance of the interception subject or other unauthorised persons becoming aware of any interception is minimised.
Postal Mail anti-forensics precautions
- Licking a Postage Stamp is likely to leave both your fingerprints on it, and to preserver a sample of your DNA from your saliva.
- Sealing a letter envelope or parcel, or affixing a postage stamp using sticky adhesive tape or glue etc. will also tend to trap possibly identifiable fibres, dust particles, hairs, skin cells and fingerprints (which may contain sufficient DNA for analysis) , or even a characteristic scent which could be used by tracker dogs.
- A single sheet letter, in an envelope with the seal along the long edge, is relatively easy to extract, examine / copy and then re-insert, simply by rolling it up with tweezers etc, and removing it through the gap in the adhesive designed to allow for the insertion of a letter opener. Obviously, with multiple sheets of paper, stapled together, in envelopes with the sealed flap along the short side, it is often impossible to do this, and the usual steaming and re-sealing techniques (or if, all else fails, a completely new envelope) would then be used
- As pointed out by irdial. Self adhesive "peel off" postage stamps are increasingly common these days and there are also now "over the counter" laser printed postage stamps and also ones which can be downloaded and printed from a web page. Such on demand printed postage stamps, and even some franking machine stamps leave a potentially traceable serial number audit trail.
- What is true for postage stamps, also applies to sealing the flap of an envelope, to Air Mail stickers, Registered Post stickers, various address labels, or any use of self adhesive tape to wrap up a parcel or packet or letter.
- irdial also suggest:
Do not use envelopes from a sealed pack. There are many places where you can buy packs of envelopes that are not sealed. In fact, these are often displayed adjacent to the Post Office queue. Why should you do this? If you use one of these loose envelopes, you can be sure that the sneezes, browsing touches, hairs and and breath traces of tens of thousands of people are going to be on them. These envelopes will be hopelessly contaminated, and that is good for you.
- Sometimes the source of your envelopes may actually be easy to trace, especially if like this malicious hoaxer Naser Ahmed, who was convicted under the Malicious Communications Act 1988, you send several postal letter threats and hoaxes "using a specific kind of envelope that was only available from one Post Office department."
- It is therefore a good idea to use gloves (and a facemask, and a hair net etc. - just as if you were handling uncontaminated food or biological laboratory samples) when touching a letter or envelope, especially as the latent fingerprint techniques have been improved recently e.g. through the use of di-sulpher di-nitride S2N2 polymer, which can "develop even very faint traces of fingerprints.. This appears to a an improvement on previous techniques for developing latent fingerprints on difficult surfaces e.g. absorbent paper, over say, "superglue" or iodine vapour fumes.
- S2N2 polymer is so sensitive, that it can pick up latent images of inkjet printed text from a letter or document which has been transferred to the inside of an envelope This sort of ink transfer, which is not visible to the naked eye, is something to watch out for if you decide to re-use otherwise untraceable envelopes, or if you print you whistleblowing document to a network printer - you may transfer traceable information to or from your whistleblower document, if it is printed in the middle of a stack of other print jobs at the same time.
Posting your mail
Mailing a whistleblower leak document requires careful choice of a post box. An out of the way rural post box, where strangers stand out as being potentially suspicious, may actually be less anonymous than a very busy urban one, in spite of the extra chances of CCTV surveillance footage..
Some large organisations have very lax internal mail systems (e.g. HMRC, which managed to lose the CDs with copies of the entire national Child Benefit database on them) , which could allow a whistleblower to simply mail an external mail envelope to their journalistic or other contacts from work, with a high degree of anonymity, especially one already franked or stamped, which is then handled by lots of people before it is sent out via the postal mail service or private courier systems.
Receiving whistleblower postal mail
Receiving whistleblower documents by mail at your normal business or home address is , of course, not advisable, if you are trying to protect your sources.
Commercial Postal Box rental, either from a private company or for an extra fee from the state postal service, has its place, but there is always a financial paper trail to the person who rents the box, and often CCTV video footage of anyone picking up mail from such boxes.
Wikileaks.org offers a supposedly secure Postal Whistleblowing service, for whistleblower leaks to them, but they do not seem to recommend many anti-forensics precautions. except regarding the serial numbers embedded into batches of CDROMs, and the unique Recorder IDs which most CD or DVD burners embed in each copy which they produce..