the feds can crack your encrypted wallets very easily. all you have to do is dump the private keys with pywallet, and save them in atext file. then you delete the wallet.dat file. rename the app data folder for bitcoin, then reinstall bitcoin. prior to launch bitcoin, move the blockchain from the old bitcoin to the new app data bitcoin folder. now start bitcoin and import the private keys. you now have an unencrypted bitcoin wallet with all the funds of the old encrypted one.