His recent tirade against the "extremely dirty domain name business" was classic Michael Arrington: forceful, well-informed — and breathtakingly hypocritical. Before the Techcrunch founder reinvented himself as Silicon Valley's leading startup watcher, and washed clean his past, he had flitted between marginal tech businesses. One of them: yes, you've guessed it, a domain trading business, Pool.com, at which the peripatetic Arrington was, for the first half of 2004, chief exec. Among other things, Pool.com marketed typo names, domains spelled similarly to well-known brands, to trick users into clicking on related advertising. So, when an indignant Arrington attacked the industry's latest "scam", one of his former business partners came out of the woodwork to remind him of his past. Delicious.

Arrington's critic was Frank Schilling, a well-known domain name investor based in the Cayman Islands, and a former client of Pool.com. In two comments on Techcrunch, now deleted by Arrington, Schilling wrote: "Your employer made a lot of money selling me domain names. So to read you labeling the 'entire neighborhood' as "dirty" after you've personally profited there, just doesn't sit well... I look at all the worthless bags of smoke that you pump on this forum, all the investors you sell down the river in these Web 2.0 jokes. Who's dirty Michael?" Ouch.

Now, let's be generous: the Techcrunch founder's stint in the domain name business is no secret. Pool.com is still listed on Arrington's Linked In profile. Let's assume too that Arrington's disgust for the domain name industry springs directly from that short stint as Pool.com's chief exec. Nevertheless, it would have been more honest for Arrington to confess to his own sins when damning the tricksters of the domain name industry. And it would, frankly, have made a better story. Self-criticism can take one a long way.

Is there any broader moral to this story? It illustrates, I think, one of the problems with tech journalism. The career reporters show poor judgement, because they've never been on the inside. Some of the most interesting news, and analysis, comes from insiders like Arrington, who has been bouncing around the Valley for most of the past decade. But they suffer, not just from conflicts of interest, but also from the perpetual risk that something they write will be at odds with something they've done, as Arrington has demonstrated here.