Se quel sito ti veniva bloccato era perchè:
Of the 2010 pages we tested on the site over the past 90 days, 47 page(s) resulted in malicious software being downloaded and installed without user consent. The last time Google visited this site was on 2012-03-18, and the last time suspicious content was found on this site was on 2012-03-18.
Malicious software includes 2 trojan(s), 1 exploit(s)...
...
No, this site has not hosted malicious software over the past 90 days.
In some cases, third parties can add malicious code to legitimate sites, which would cause us to show the warning message.
Rischi insiti in questo tipo di siti.
Curioso che Firefox basandosi su questa analisi di Google ti abbia bloccato l'accesso al sito e Google Chrome no. Forse che il primo è più sicuro del secondo?