The down side to Truecrypt files is that information about the contents might leak onto the unencrypted parts of the hard drive. For example, if you open a document that is stored in the encrypted file, it may be added to a Recent Documents or Recent Files list in whatever program. Take a look at the traces that the browser bundle leaves behind on Windows: http://dkn255hz262ypmii.onion/index.php?topic=148291.msg1152452#msg1152452 Presumably some of those traces are left behind when it is run from an encrypted file too. Full disk / volume encryption, where there is no unencrypted area to leak data to, is much safer. But Tails isn't really about the encrypted persistent volume. That's just one feature. Even if Truecrypt volumes were just as good or safer, the reasons to use Tails include: -- it's Linux, so there's effectively no malware to worry about <-- this is the main reason it's safer -- it transparently torifies network connections <-- the second biggest reason -- it comes with many apps that are configured to use Tor -- it implements new Tor features early, such as obfsproxy bridge support and stream isolation -- it never touches the main hard drive, so there is absolutely no data leakage -- it's run from media (DVD, USB) that is easy to get rid of Tails is definitely safer than running TBB from a Truecrypt file on Windows.