Michael Calce, the reformed hacker from Montreal who will forever be known as Mafiaboy, told a group of IT professionals Tuesday that he has serious concerns about the inherent vulnerabilities in the latest evolution of information technology: cloud computing.Calce was a guest-speaker at storage vendor Hitachi Data Systems' (HDS) (NYSE: HIT) annual Information Forum event in Toronto. He came to fame in 2000 when, as a teenager, he launched a series of denial of service attacks that crippled the Web sites of companies such as CNN, Amazon, Dell and Yahoo, leading to a manhunt by the RCMP and the FBI and his eventual arrest.Having completed his sentence and matured beyond the "misguided youth with too much power at his fingertips," Calce is speaking-out about IT security and the inherent vulnerabilities in the way the Internet is constructed that he said still haven't been addressed. And Calce has some serious concerns about the latest craze sweeping the IT industry: cloud computing