writes "Trend Micro has accused ClamAV of infringing a patent it owns, #5,623,600. It specifically has named Barracuda Spam Firewall, the Barracuda Web Filter, and the Barracuda IM Firewall as infringing. Trend Micro has been trying to get Barracuda to either pay license royalties for including ClamAV or stop using ClamAV in its products. Barracuda is an Open Invention Network licensee, and it decided to stand up and defend ClamAV against what it views as a bogus claim. Barracuda believes the patent is questionable, at best, and believes there is prior art to be found and is seeking assistance to find it."