it looks like the registrant's address for the .com version has changed. It used to be (about 6 months ago) 155 Regents Park Road, London (which is a mailing address). It is, now, according to a 'whois' from the UK:
whois -h whois.opensrs.net aljazeera.com
Registrant:
AJ Publishing
Sheikh Zayed Road
Dubai, Dubai PO Box 31303
AE
Domain name: ALJAZEERA.COM
Now, the TV channel is the one based in Doha, Qatar; so the .com address, although they now give an address in Arabia, is still 'someone else'. Their stories are not the same as the ones (in English) at alljazeera.net. In fact, they now have an 'about us', which includes the Dubai address:
About Aljazeera.com
Aljazeera Publishing owns and operates Aljazeera.com, bringing you the world today. Aljazeera Publishing is an independent media organisation established for more than 12 years delivering news and analysis to readers all over the world. Aljazeera.com has a particular focus on events and issues in the Middle East covering major developments presenting facts as they happen.
http://www.aljazeera.com/about.aspSo, they say they are publishers, not broadcasters. There is nothing to say they are in any way related to the broadcaster. I think they should be treated as a website of unknown ownership, whose agenda is also unknown, and so no more trustworthy on its own than a blog or, say, DU. Not, I would say, a primary news source of any kind.