The writing has been on the wall since AOL purchased Michael Arrington’s family of TechCrunch sites last August for $25 million. AOL also snapped up Engadget as part of their 2005 acquisition of WebLogs, a blog network with over 75 blogs of which Engadget was a member of at the time.

But lately, it looks increasingly as if the fact the two rival blogs share the same owner did not sit well with Michael Arrington, TechCrunch’s founder pictured on the right.

A week ago Arrington posted on TechCrunch a story titled "Real Blogs Don’t Buy Ads On Google" that accused Engadget of buying traffic via Google ads in order to draw more clicks to their stories:

One thing big blogs don’t do is buy traffic to juice up the Comscore numbers. It’s an unspoken rule. It’s cheating, and it brings in bad traffic that doesn’t stick around or come back for the most part (or so we assume).

Some readers saw the quarrel as Arrington’s whining about selling out while others pointed out that TechCrunch is getting a nice big reach-around from AOL. A series of ensuing posts suggested to onlookers that Arrington was trying to fire himself.

He accussed Engadget of being not just an "immensely unethical" publication, but a "plasticized caricature of a real blog." But why attack a sister blog and fellow AOL employees?

Traditional newspapers like the New York Times soon picked up the story and it blew up from there on. According to San Francisco Chronicle, Arrington has been "telling people that Engadget tried to spike AOL’s acquisition of TechCrunch" and Arrington’s follow-up post on TechCrunch shared this sentiment.

Tech entrepreneur Michael Arrington, 40, is well known for his cocky character and readiness to ignite flame wars, the strategy that served his various blogs well thus far. Part of what makes this ugly public brawl even more strange is the fact that Arrington is contractually bound to lead TechCrunch blogs for three years for a hefty bonus.

Should he quit before this contract expires, he would lose the bonus but retain the $25 million. Engadget managed to stay on the sidelines without responding to Arrington’s unpleasant accusations until Joshua Topolsky, the blog’s editor-in-chief and a record producer, drummer and DJ showed on the left, fired back in the comments of a Business Insider piece:

Mike. Enough is enough. Explain what we’ve done to you. Explain anything that you’ve said beyond a personal vendetta. I haven’t heard a shred of substance behind your attacks — only the vitriol of a man-child who can’t control himself. "Immensely unethical"? Explain it.

Arrington did not respond. This catfight is getting interesting from the journalist’s point of view. It remains to be seen however, how long before AOL has enough of this damaging behavior and asks Arrington to either calm down or leave the company.