Bitcoin is actually the biggest password-cracking operation in the world. Project "satoshi" is it's NSA name. For just a few million dollars offered in "reward" to keep the "market value" up, the government can now crack just about any password in minutes, thanks to your help in creating a 125,000 teraFLOP-equivalent distributed machine!
Don't believe me? Current SHA password hashing takes about 1400 instruction cycles, significantly more complex than md5.
There are 92 characters that can be typed on the American keyboard, of those about 70 are common (26+26+10+about 8 punctuations). That's 70^11 combos for an 11 digit long password, and we generally solve it hashing less than 50% of the key space even if you make it complete gibberish. That's around 100,000,000,000,000,000,000 hashes we have to calculate to solve 11 digit long passwords. 140,000,000,000,000,000,000,000 compute cycles on average for the most complex non-dictionary attackable passwords.
Bitcoin offers 125 exaflops processing power, specifically optimized for solving hashes. That makes the maximum-complexity non-dictionary random-character 11 digit password crackable in 14 days, 10 digit passwords in four hours. Attacking first with limited character set rules and dictionary words makes most passwords about 0.001% that complex. 13 digit passwords are also solvable 50% of the time by adding "69" to the end, you perverts. BTW each of you are assigned a few dictionary words the mining software randomly scrapes from your hard drive's documents or clear text in binaries. The hash of that is called your 'wallet'.
Please keep doubling the processing power every month for the government. Setec Astronomy.
edit: duh, of course this is a joke, notice the last paragraph gets more silly, but it is also interesting philosophically how money makes so many people come together and dedicate computing resources to solving a non-problem.
That is why I am in favor of using a more advanced forms of captcha, and if an incorrect password is entered, require a time delay of five minutes after the third password entry attempt fails.