Unscrupulous owners and managers:
There is a chance that the person running the internet cafe might be involved in the internet business or the identity-theft business.
Phony 'customs' or internet-cafe patrons are there to spy: Some cyber criminals can see precisely what you are typing regardless of how fast you can type.
The visible security cameras are for public safety; while the invisible cameras could be recording all windows viewed and each keystroke made, together with recording all 'immoral' acts by users in the booth; to be later used for blackmailing purposes.
Being used previously by cyber criminals is also a possible.
The cafe manager could install spying devices that would record each keypad movement. Such devices are impossible to locate, without disassembling the computer.
Unsafe Wi-Fi devices:
Internet cafes often provide local Wi-Fi hot spots.
The information even if encrypted could easily be accessed by Wi-Fi spes.