Biggest security purchase since Intel wolfed down McAfee Intrusion prevention's a hot topic in the world of security, as reflected in the $2.8bn price tag Cisco has paid to complete the acquisition of network security specialists Sourcefire.The purchase - which was announced in July - is the largest security firm purchase since Intel's $7.7bn acquisition of McAfee in 2010. And it's a huge personal payday for Marty Roesch, creator of the open-source intrusion protection system Snort. He took Snort's basic technology and built commercial code under the Sourcefire brand since 2001."I'd be lying if I said I wasn't sentimental. When...