The Tor Browser Bundle says it uses firefox 10 the current version is 24
Firefox is version 3.5, the current version is 26
IE is version 8, the current version is 11 (as far as I know)
iPhone is iOS 3_1_2, the current version is iOS 7_0_4
These combined with #47 this makes users stand out a lot
This makes it easier to single out user traffic
Examples
The Tor Browser Bundle says it uses firefox 10 the current version is 24 Firefox is version 3.5, the current version is 26 IE is version 8, the current version is 11 (as far as I know) iPhone is iOS 3_1_2, the current version is iOS 7_0_4
These combined with #47 this makes users stand out a lot