Wadja.com has sent out a statement describing Facebook as the "anti-social network" and accusing it of "Big Brother-style" tactics.
Facebook users are barred from mentioning either Wadja.com or Wadja.
When users try and send a message with the word 'Wadja' in it, they are told: "Content rejected. Some of the content you included in this message is not allowed by Facebook".
There is also a ban on mentioning another social networking site, Yuwie.com; the ban was put in place after Facebook members complained about it spamming groups.
Facebook's director of communications, Brandee Barker, has told the RWW Network that Facebook has measures in place to protect users from spam and other unwanted contact.
She said: "When we detect that certain content is being used to spam or harass, as in this case, we may block it so that it can no longer be posted or sent."
Wadja.com, which is undertaking launch activity in the UK next week, is an "open wall" social network -- allowing users to communicate with friends who are signed up to other social networks, including MySpace.
However, it denies that this opens members of other networks to spamming, because it works on a peer-to-peer system and users have to give permission before they can receive messages.
As well as banning mentions of Wadja, Facebook is blocking messages sent from Wadja to Facebook users.
Alex Christoforou, managing director at Wadja.com, said: "This move goes against the very principle of social networking -- easy communication.
"It even goes against Mark Zuckerberg's own words at South by Southwest Interactive, placing Facebook as a modern communication platform that could connect people in new and exciting ways."