It's not hot any more, but did you ever thought what was the claims and what was the patents.
now a days patents looks some form of evil which stops creativity( creativity is defined as "making workarounds" so that ppl can reinvent wheels than using them.
Here goes the list of patents vonage infringled and an analysis
A Detailed analysis :
yankandpaste from : hey man, i am also making workarounds , I am creative :-))