Software developed by corporations is usually the property of the company that produces it. Those companies usually keep the source code secret, considering it to be trade secrets. However, this proprietary software also means the producing company can easily insert malicious code or secretly collect information about the user and, even worse, allow others to see that information.
One example is Skype, a company acquired by Microsoft. Recent documents released by Edward Snowden show that Skype, and now Microsoft, has been under order from the secret US Foreign Intelligence Surveillance Court (FISC) since February 2011 to not only supply information to the NSA but also to make itself accessible as a source of data for the agency. In other words, whatever conversations you have over Skype are accessible to the NSA. That agency has also been known to share all sorts of information with the FBI, other law enforcement agencies, and with foreign governments.
Skype is one obvious example but undoubtedly not the only commercially-produced software that gives information to the corporation’s employees and to other organizations as well.
In contrast, open source software makes it difficult for anyone to insert secret back doors without it being noticed. Too many programmers’ eyes are looking at the source code of open source software to allow anyone to add anything malicious to the programs. Open source software is also available free of charge. In fact, it is often called FOSS, an acronym for “free and open-source software.” You can read more about FOSS on Wikipedia at http://en.wikipedia.org/wiki/Free_and_open-source_software.
One excellent example of FOSS is Off The Record, usually called OTR, a cryptographic protocol that provides encryption for instant messaging conversations. Transcripts of intercepted chats using OTR encryption handed over to the NSA by a partner in Prism — an NSA program that accesses data from at least nine American internet companies such as Google, Facebook and Apple — show that the NSA’s efforts appear to have been thwarted in these cases: “No decrypt available for this OTR message.” This shows that OTR makes communications impossible to read for the NSA.
The ZRTP protocol, which is used to securely encrypt Voice over IP (VoIP) voice communications and text chats on mobile phones, is used in free and open source programs like RedPhone and Signal. Other open source products include the instant messaging system CSpace and Tor, an anonymization network service.
GNU Privacy Guard (GnuPG), an open source program developed by German programmer Werner Koch encrypts messages. One document shows that the intelligence services use PGP themselves to protect their own communications from other snoops. That is high praise indeed! The fact is that hackers obsessed with privacy and the US authorities have a lot more in common than one might initially believe.
Likewise, the Tor Project was originally developed with the support of the US Naval Research Laboratory to protect the privacy of U.S. governmental agencies. However, the software is free, open source, and is legally available for use by anyone.
If you are interested in personal freedoms and privacy, you need to use open source software. Make sure you always obtain the software from the original producers, not from a third-party that may have modified the open source software.