explain front row sharing plez

hi i only just took a look around front row on my new macbook and when i went into shared videos up came "PC use library". i work in a college and was connected to the ethernet at the time.
so is this someone elses computer in the building? when i play their videos/music does it slow down their computer? and how do i stop them accessing mine?
thanks.

If those files weren't on your computer, then yes, they belonged to some other person. If you play the files, you won't necessarily slow their computer down, but you will take up their bandwidth. So the person will definitely notice a slowdown in his/her internet connection.

I believe sharing is turned off by default on Macs. You actually have to go into the Sharing Preferences and turn on the services needed for other computers to use your files. So you don't have to worry about somebody else accessing your media files.

thanks, from the look of their computer name its a PC with itunes that i was accessing on the network. theyre gone now, either it was a laptop that was disconnected or a computer which has since been shut down.