>Have you ever seen any (successful) community service that sold licenses?
Yes, Akismet spam. (anti-spam system). It blocks the spam on here quite well, and works with user tagging. Free for basic use, pay for commercial.

A problem with my idea is that selling it is that most people in a position to buy it probably LIKE the type of spamming I’m speaking of. They make money with infrastructure on ALL internet traffic, not just the good kind.

First of all I’m not sure if it’s really that big a problem. Maybe I just don’t visit the places that you do or maybe it’s just the right time to start doing it so that it will be good enough when it will be needed.

Some thoughts and critics. First of all, logging the IP is worth almost nothing. I don’t know how those guys work but if I were them I would use a special application to make things faster. And then it would be really easy for all of them to go through an anonymizer proxy. Just a config setting from the HQ.

Then the links can be tricked too. Just use a redirection service like tinyurl.com. OK, it’s not really a showstopping problem because the service itself can also check if there is a redirect. Habits are a good thing to filter on because they are hard to cover or change. They are just hard to learn and process programatically. I’ve read an article about how the forum users are actually given away by their very own comments. Some university did some research project where they were quite successful in identifying the users by their comments. And of course the ‘other things’ part is hard too But probably filtering the urls is good enough as a first iteration.

But then there is the problem of all such systems, you have to somehow filter or recognize the malicious users. If you build such a system then the guys who are affected will attack it with false data. This is usually the point I always stop thinking but probably one can find a good enough solution to this (e.g. by using collaborative filtering or by calculating a trust metric for each user and the new ones always start with low trust).

The biggest problem I can see is that there is really now money in here. At least not the way you think there is. I don’t think that anybody would pay for anything like this. Why would anyone by a commercial license? Or what is a multiuser license? Have you ever seen any (successfull) community service that sold licenses?

The only way you can make money out of this is going the ‘web2′ way (hate this word ): get famous, get big, get bought out. Or instead of being bought you can use this site as a very strong marketing tool if you have a startup. That’s not a bad option BTW. I’m working on a few things that will hopefully bring money this way. OK, there is one more possible way: open the API and let big blog and forum providers use it. Try to get some money from them (or increase the chance of being bought out by one of them). The open API is a must anyway.

I used to be on a cracker forum, now defunct.

The moderator got sick of script kitties on the site and added code that added a big red “AOL USER” tag on all AOL users’ posts.

(Idea somewhat inspired by Pirated Phono Phunk after I changed the CSS.)