I was asked by someone to comment here, since I wrote brainflayer and have coauthored two papers about brainwallet cracking.
I am really surprised by the collective refusal of brain wallets. It all started roughly two years ago when suddenly a secret society of crypto guys started a war on brain wallets ... including popular ones like brainwallet.org that I have used thoroughly back then.
Haven't I seen you posting
https://bitcointalk.org/index.php?topic=421842.0 in the past about cracking bitcoin keys? Hard to tell, since you've tried to purge your old posts, but your motivation here is highly suspect.
What motivation do you think us "crypto guys" have for trying to prevent people from using brainwallets, other than to save people from themselves?
This "research" paper does not say how many bitcoins they have collected as the result of cracking brain wallets.
You didn't read the paper, then. Threads on bitcoin talk where people are bragging about cracking brain wallets are listed. Hundreds of BTC have been taken.
I have personally had correspondence with people who have lost over 100BTC due to forgetting their brainwallet passphrase. I spoke on the phone with someone who lost about 47k ether from a brainwallet.
If someone wants to store bitcoin using a memorized secret, they should use BIP39, optionally combined with BIP32, and use spaced repetition to memorize the seed.
If you absolutely insist on coming up with a passphrase yourself and storing bitcoin with it, go use WarpWallet with your email address, name, or phone number as a salt. It's several orders of magnitude more secure against cracking, and multiple independent implementations of the algorithm exist.