Of interest to the people here, it should be noted that the company sought to continue their activities through a TypePad blog (hosted by SixApart, the same company that now owns LiveJournal) they redirected their domain to through DNS, but the spammer simply launched a massive DDoS on TypePad, which affected LiveJournal as reported here by LJ staff.
The spammer reportedly told Blue Security in an ICQ conversation that if he can't send spam, there will be no internet.
UPDATE: This blog seems to give some more information. Also, some work colleague just came up with the analogy that spammers were like drug dealers. Blue Security were doing the same as organising vigilante action against the drug dealers. So what do the drug dealers do? Send round their heavies to 'deal' with Blue Security. Pretty dumb, all in all. Blue Security's actions haven't helped anyone, just annoyed them.
UPDATE2: Interestingly, Blue Security appear to be out of business.