In a strange coincidence with Facebook's Monday announcement that it has over 600 million users, Pope Benedict cautioned that online friendships are no replacement for real human contact.

Urging his followers to connect with other in the real world, instead of the social networking route, the Pope - in his message on the occasion of the 45th World Communications Day by the Catholic Church - said that young people, in particular, should be "authentic and faithful, and not give in to the illusion of constructing an artificial public profile for oneself."

He also added that truth is, in no way, driven by the "popularity" of the online presence of a person.

The Pope's speech, which was made public by the Vatican on Monday, did not mention any specific social network; even though the news was released via the Vatican's English-language Twitter account as well as others.

Praising the social network for having extraordinary potential and providing a "great opportunity" in terms of communication, the 83-year-old Pope warned the fanatic users of the risk of depersonalization, isolation, and self- indulgence, as well as the dangers of having more virtual friends than real ones.

In his speech, the Pope - who, on record, does not have a Facebook page - essentially portrayed the social media as "not only changing the way we communicate, but communication itself, so much so that it could be said that we are living through a period of vast cultural transformation."