Wikipedia is prone to vandalism, but how much of a problem is this, compared to errors in traditional reference works being uncorrected for several years?
The vandalism is obvious and infantile and is partly in Norwegian in an otherwise English article: It claims that Stoltenberg headed "norske Sjimpanse Ape forening" (the norwegian chimpanzee monkey society), won the election by fraud, and has been in prison for "paedophilia" (sic!). The vandalism was conducted at November 9th, 2005, it was removed within 24 hours, and can be traced to an IP address belonging to a regional network in southern Norway that connects a large number of comprehensive schools to the Internet.
Yes, Wikipedia is prone to vandalism. Users of the Wikipedia should know about that and not take everything they find in it at face value. Misinformation in an encyclopedia is bad, but this incident prompted me to check out how Wikipedias two major online competitors, Encyclopædia Britannica Online and Microsoft's MSN Encarta [now defunct] – both with conventional editorial staff behind them – measure up.
As it turns out, neighter encyclopedia features a biography on Jens Stoltenberg yet.
As for accuracy, the article on the Kingdom of Norway in Encyclopædia Britannica Online still lists Kjell Magne Bondevik as the country's prime minister, but curiously adds a note that he will be succeeded by Stoltenberg on March 17, 2000. I.e. Britannica hasn't been updated for five years! They've have left out both the 2001 election, when Bondevik regained office, and the 2005 election when Stoltenberg won.
MSN Encarta is significantly more up to date. Their article on Norway mentions the 2005 election and Stoltenberg becoming prime minister, but that's about it.