The hackers claim that the data was retrieved from a hacked server that the former Prime Minister used last year and, says the Reuters newswire, includes names, home addresses and email plus phone numbers of Blair and his office staff, as well as large numbers of his friends, family and colleagues.
The Softpedia newswire, meanwhile, claims that the CV of Blair's special adviser Katie Kay was also published.
"On their Twitter feed, Teamp0ison wrote that `Tony Blair is a war criminal, he should be locked up.' The group is known to be driven by political motives and believed to be anti-US, anti-Israel and anti-India", says the newswire.
According to editor Lucian Constantin, the Dutch hacking group's members are known to have worked with the Pakistan Cyber Army and Mujahideen Hacking Unit to attack and deface US government and military websites.
The group, he notes, is currently trying to expose the identities of LulzSec members. Their main beef with the group, he asserts, that has been wreaking havoc online for the past few weeks is apparently their lack of skill.
"Stop telling yourself that u are hackers, putting a ip into a irc is NOT hacking nor is using pre-made tools and scripts to grab database - you do not represent the anti-sec movement, u are not allowed to greet underground groups like zf0, ab, h0n0, el8", Teamp0ison reportedly wrote to LulzSec", says Softpedia.
According to Chester Wisnieski, a senior security threat advisor with Sophos, the nature of the vulnerability exploited to break into the webmail server is not known, but there is a strong possibility that the compromise was the result of outdated software.
"It is extremely important to keep web servers patched and up to date, especially if they are running Linux using commonly exploited CMSs, webmail solutions and blogging software", he says in his security blog.