http://www.npr.org/blogs/thetwo-way/2009/11/nsa_microsoft_windows_7.html

The National Security Agency has been working with Microsoft Corp. to help improve security measures for its new Windows 7 operating system, a senior NSA official said on Tuesday.
i'm not sure what to think about this revelation. on the one hand i, and quite frankly many others, have long suspected that microsoft had a backdoor built into windows so that certain members of the intelligence community could gain easy access to pc's running windows.

the case for such an arrangement is quite compelling:

1) there are laws that restrict the exportation of hardware and software that can be used for encryption and decryption. these laws rely on a list of countries, with certain countries are flagged as prohibited when it comes to the exportation of said technology, which includes even such seemingly benign devices as the playstation one.

2) bypassing windows logon protections has been a trivial task since the NT days, all one has to do is hash the SAM file, which holds all the information regarding user id's and passwords.

3) microsoft itself offers a tool for law enforcement tool called COFEE that they claim can bypass any systems security easily:

http://www.microsoft.com/industry/government/solutions/cofee/default.aspx

Microsoft has created Computer Online Forensic Evidence Extractor (COFEE), designed exclusively for use by law enforcement agencies. COFEE brings together a number of common digital forensics capabilities into a fast, easy-to-use, automated tool for first responders. And COFEE is being provided—at no charge—to law enforcement around the world
4) the fact that the NSA is authorized by executive order to monitor any communication, phone call, email, text message, internet activity, smoke signal, of any person believed to be engaged in terrorist activity.

on the other hand, i don't believe for a second that this type of backdoor is solely limited to windows variants. apple has to comply with the same laws, as do the various linux vendors. as such, while the indie linux distributors, like vector are most certainly backdoor free, i don't think it's a stretch to assume that all variants of os x and solaris have backdoors in then, as i'm fairly certain redhat's and novell's linux distributions do as well.

for those that think linux, by virtue of it being open source, is immune to having any type of backdoor, i would point them to red flag linux:

http://www.redflag-linux.com/en/

when this distro was first released, it was marketed as a linux distro developed by the chinese government for the chinese market. they have since changed their site to make it appear as if it's the result of private enterprise, with claims that it was developed by an asian consortium, but i still remember when it was first released about 10 years ago, and considering china's track record on civil rights, with routine crackdown's on free speech and free press, as well as their censoring of the internet content available within china, i find it hard to believe that they would allow the marketing of any os within it's borders that didn't have a built in way of bypassing an individuals security measures.

what it comes down to is this: if security is a concern, for any reason, a staggered approach is best, use the included default security tools available within an os as a way of throwing people off the trail, use a strong password for login, use included encryption software, but add a layer of third party encryption underneath it and then use some clever misdirection techniques, such as changing a files extension and placing it in a completely unrelated folder, to throw anyone that tried to snoop off the trail.