NORTON Antivirus 2012 - 3 PCs - must the 3 PC's be at the same home/office address?

NORTON Antivirus 2012 - 3 PCs - does this product require that the 3 PC's are in the same home or office address? I have 3 friends who will now be working from home and need to buy anti-virus software for the new year. They will all be in their own different homes. Can they share this product or do they need to buy 3 individual copies of Norton Antivirus 2012?  Does the 3 pack look at the telephone no. for the internet access?  Thanks, Alan