If he really is that upset it is still in print, why doesn't he use at least the sum of money that he originally earned from the book in efforts to take the book off the market somehow?"

I seriously doubt if he made a dime. From the Amazon page:

I have recently been made aware of several websites that focus on The Anarchist Cookbook. As the author of the original publication some 30 plus years ago, it is appropriate for me to comment.

The Anarchist Cookbook was written during 1968 and part of 1969 soon after I graduated from high school. At the time, I was 19 years old and the Vietnam War and the so-called "counter culture movement" were at their height. I was involved in the anti-war movement and attended numerous peace rallies and demonstrations. The book, in many respects, was a misguided product of my adolescent anger at the prospect of being drafted and sent to Vietnam to fight in a war that I did not believe in.

I conducted the research for the manuscript on my own, primarily at the New York City Public Library. Most of the contents were gleaned from Military and Special Forces Manuals. I was not member of any radical group of either a left or right wing persuasion.

I submitted the manuscript directly to a number of publishers without the help or advice of an agent. Ultimately, it was accepted by Lyle Stuart Inc. and was published verbatim - without editing - in early 1970. Contrary to what is the normal custom, the copyright for the book was taken out in the name of the publisher rather than the author. I did not appreciate the significance of this at the time and would only come to understand it some years later when I requested that the book be taken out of print.

Pretend you're an angry teenager with delusions of grandeur with a side of paranoia (" I was being actively pursued by the US military, who seemed single-mindedly determined to send me to fight, and possibly die, in Vietnam"). You spend your summer hanging around the NYPL scrawling insurgent shit in your 3-ring binder as you peruse US Army survival manuals. Now you've got this big stupid thing full of half-truths and poorly-understood military tactics; a publisher offers you $100 ($600 in today's dollars). Do you take it?

That's a guess at the number, but I'll bet the situation played out a lot like that.

No matter what he's made money off the book. Until he shows he's really upset about the book still being out there by using that money to do something other than further himself, I'm not convinced he's really that upset about the book being out there. You can't profit from something and simultaenously harp on about how terrible it is.

On the one hand, I doubt there was much profit. On the other hand, the dude's a stone-cold narcissist if he thinks his book ever mattered. Listen:

We had ample access to The Anarchist Cookbook. Everybody did. Leaf through a few pages, however, and you'll quickly surmise that it was written by an angry 19-year-old lifting things he barely understood from library books. It's got a recipe for Bananadine, FFS.

I had a dozen books from Delta Press (purchased under a pseudonym, which still gets batshit crazy mail at my dad's house). There was a sense of batshittery to most of them - even a moderately clever 18-year-old could poke holes in their theories - but none of them held a candle to the lunacy presented as fact in The Anarchist Cookbook. There are a few tidbits that were clearly lifted from Army field manuals, but like the guy says, you could find those at the library.

The bottom line on The Anarchist Cookbook is it's a manual for the mujahedin but they never touched it. It's all about improvised weaponry and insurgent tactics but no one with a real interest in improvised weaponry or insurgent tactics is ever caught with one in their possession. It's a red herring - a tall tale for angry children. That's why it's always been marginal, that's why it's always been hard to get, and that's why no one has ever really gotten serious about taking it out of circulation: so much worse is available easily and readily.

The fact that William Powell is still trying to make this about him says a lot.

Doubt it, for more or less the reasons kleinbl00 outlined. I can see a kid like him taking two months rent and thinking it's a steal. Still happens pretty often to new young writers, because publishers hold all the cards.