ATBB was started by Laura London, a fan of Belichick's since his Cleveland days, in 2000 and for the past ten years has been the go-to site for stories, press conference transcripts, photos, interviews with the coach, statistics, you name it. Many of us, I'm sure, know the site and Marima frequently links to pieces that Laura has posted. The most valuable thing to me was the archive of press conferences. If you ever wanted to know what Belichick said after, let's say, the Dallas game in 2007---and I know I wanted to go back and re-read it--all you had to do was click on the links. The site also had stories and quotations and interviews and all kinds of things. I checked it daily during the season and pretty regularly during the off-season. It was a phenomenal archive of information for research (and as a college professor myself, I'm kinda big on research). Last fall, I was the first to answer the trivia question "Quote of the Day" on the site and I'm now the proud owner of an autographed Bill Belichick photo, something that would not have been possible without the website.
I don't know the whole backstory--except that it sounds messy and unpleasant--but the website allthingsbillbelichick.com is now finished. All Patriot fans and all Belichick fans lost a valuable place in cyberspace for tracking our favorite coach.
As I noted, it sounds like the ending of this site was particularly unpleasant (click on the site for a link to Laura London's twitter postings that detail how things fell apart). Some of it was hostility towards her and the site; much of it seems to be that, like many independently run and maintained sites, it simply couldn't make enough money to sustain itself. Eventually, even a labor of love can become too much to maintain.
I'm sorry to see this development. ATBB was a great site and it existed for ten years, an eternity in the web-age. I'd love to know more about the behind the scenes events that led to its demise, but whatever the circumstances, Patriot nation is poorer today for the loss of a great website dedicated to our coach.