In order to properly password protect USB drives and the information that they hold from the clutches of people in the business of identity theft, we really need to be very careful as to where we decide to get our protection from. There are software programs that provide a means to password protect USB dives and the personal data therein, but not all are created equal... in fact, some may actually put all of your data in deep jeopardy.
The use of freeware programs or shareware can seem like a good thing, because they can be freely downloaded from the internet at no cost, or at least so it seems on the surface. Truth be told however, many (if not all) of these have mixed in within the program things known as adware and spyware, which may serve as a means of securing a bit of a passive income source for those that programmed the software and/or those that supplied it. But through such insidious programs, much or all of our data is laid bare online, and completely and utterly defeats the whole original purpose of downloading the program in the first place, which was to password protect USB drives from just such foolishness. Well, you know the old saying, "you get what you paid for".
Investing in professionally created software to password protect USB drives is the only true way to protect your data from unscrupulously prying eyes. The cost of these top-notch security software programs aren't very costly at all... the price of a few cups of java are all you would pay for some. But as far as guarding your private and personal (and perhaps even financial) information, please don't toss up your trust to a free download - invest... invest in the best security you can find.