That might be a bit extreme, every time it's happened on my forum it's been an honest mistake- the user had no idea the domain they linked to had malware issues. Not everyone uses good virus scanners... (but they should.)
yeah not all, only the one that i suspected the owner of the malware site
maybe some one should create a member article about this in Articles forum? how to step by step to overcome this malware warnings from google, and how to avoid it for future