The most important thing to do with these kinds of software is to set a password! If it was to get hacked they could copy all your personal files, retrieve passwords etc... & then even delete files from your computer and shut it down. So be carefull who you let access it.
Saying that though, it's a really handy thing to be able to do. Especially if your at work and need files on your home computer.
Obviously you need your computer on and connected to the internet for this to work.