I followed an interesting discussion this past week. It started as a discussion of some security vulnerabilities that were released by a security researcher. "Abe" got all worked up, saying that this researcher should be prosecuted for releasing the details of the security hole so anyone would be able to take advantage of it.
The importance of openness in security was brought up, specifically how big software companies will generally try to hide vulnerabilities to protect the illusion of security, as opposed to the way open source projects just acknowledge and fix the security holes.
The conversation somehow turned into Abe accusing someone else of participating in an underground economy and personally benefiting from using free software at the expense of taxpayers, who are paying his salary (which is so false it doesn't even merit a reply). He continued on pointing out that free software isn't actually free, since there are all kinds of costs associated with it.
Of course there are costs associated with any software. The "free" doesn't mean that there are no acquisition costs but that once you have acquired it, you are free to do with it what you want. Proprietary software generally costs up front to purchase it, and then you are at the mercy of the software developers to make changes to the software if that is desired or needed. If you need a new feature and they don't want to implement it, you'll never get it. With free software, you may or may not pay up front to purchase it, but you are of course likely to invest in training, hardware, and other costs to actually implement it. The nice thing is that once you've implemented it, if you need a new feature, you can just add it or pay someone else to add it. If the original developer won't do it for you, it doesn't matter. You're free to change it if you want as long as you're willing to share your changes with others.
It was pretty obvious to everyone else that Abe didn't know what he was talking about, since he kept referring to money instead of freedom, so someone finally called him a troll. It didn't end there as he made a joke about trolls that showed he didn't know what a troll was. Someone else referred him to Wikipedia's article on trolls, after which Abe backed off and claimed he was just acting as devil's advocate and pointed out that the debate could just go back and forth all day so wasn't worth continuing.
I'm pretty sure he didn't understand all the arguments against his position or else he was the dumbest devil's advocate ever. Either way, he realized he was outmanned. The biggest piece that he was missing was not whether there are costs associated with implementing free software but that there are very real costs associated with not being permitted to maintain proprietary software yourself after implementing it. Can you really afford the lack of control over whatever platform you deploy if you use something other than free software?