Don't Take Candy From Strangers
When you have an internet connected device should you really be just downloading and taking files from strangers ?
One , you do not know what you are downloading in many cases and you don't know what comes with these files.
Two - usb devices that are passed around should not just randomly be inserted into computers - you dont know what is on them and many organisations will even go to the extreme of glueing up the usb ports.
Three - free software usually comes with some caveats - which can include malware , adware
So be careful and don't take candy from strangers