Blogs originally formed a “commons,” even according to a narrow and technical definition of that term. They were always privately owned, of course. I’m the only person who can post here, because I pay the $9.95 monthly fee. However, the whole array of blogs, the “blogosphere,” originally had an un-owned feel. That was because you could visit any site you liked, and any blogger could link to anyone else. The blogs with the most incoming links were the easiest to find through search engines. Therefore, prominence was difficult to buy; it resulted from others’ “gifts” of links. Most blogs also permitted visitors to post their own ideas in the “comments” field, thus opening up space for free discussion. Finally, the clever “trackbacks” feature notified bloggers when their posts were discussed on other blogs. For example, when another site links to mine, it often sends a “trackback ping” to let me know; that site is then automatically listed here (under “links to this specific post”) so that you can see who has written something in response to me.

In short, the network of interlinked blogs belonged to no one, it was unaffected by money, and it was open to newcomers. In all these respects, it was a commons.

All commons are fragile. One form of the “tragedy of the commons” is pollution.

The first pollution to hit blogs was simply the obnoxious comment–a price we always pay for liberty. Then came a more insidious problem, “comment spam.” In order to increase their ranking with Google, pornographers and other bottom-feeding capitalists started placing comments on blogs that were really just links back to their own sites. They used software to place these links automatically. At the low point last summer, I occasionally received more than 100 comments per day that advertised various illegal pornography sites. I removed them quickly, but it was a big nuisance. Finally, by making it more difficult to post comments and by changing some technical aspects of this site, I reduced the problem to a manageable level. Since many other bloggers took similar steps around the same time (or stopped allowing comments altogether), “comment spam” became generally less efficient and profitable.

So the bad guys discovered “trackback spam.” It’s simple: they link to specific entries on blogs like mine, thereby getting themselves automatically listed on my site. Again, they use software that places the links automatically and rapidly. I now receive scores of incoming links every day, mostly from gambling sites. These trackbacks are very hard to remove using my blogging software (MovableType 2.64). There are many hundreds scattered through my archives. Although I remove offending trackbacks when I find them, I have left most of them alone because it’s just too time-consuming to delete them. A link to a gambling site is not terribly offensive: not like a comment that actually describes some disreputable product.

However, Henry Farrell and Brad DeLong are now arguing that massive use of trackback spam could spoil the whole blog “commons.” (By the way, I just sent them “trackback pings” by linking to them in the previous sentence; but my motives were pure.) If most links have nothing to do with the content or merit of the target site, then we will no longer be able to find popular blogs, or similar ones, by following links. Mechanisms like Technorati, which uses the link structure of the blogosphere to derive interesting information, can be badly damaged by trackback spam. You can even imagine popular sites selling links, which would make prominence a function of money.

As I’ve previously noted, the blogosphere never met ideals of equality or meritocracy. However, trackback spam will make things considerably worse–much as email spam has spoiled that medium. Bloggers could fight back by modifying software to prevent trackback spam and removing the spurious links. In my case, that would mean upgrading to more recent software and transferring all my archives–a pretty time-consuming process and one that I could easily screw up.

If we all took steps to block spam, it would go away. One should always do what one wants everyone else to do. That’s the moral argument for taking the time to upgrade my site. The counter-argument is simply that I have other things to do with a whole day. … Occasionally, when email spam, viruses, comment spam, and other nuisances really get me down, I wonder, “What’s so great about the Internet?”