Everything has to follow the Terms and Use of Freebitco.in - please read them.
You can't use the freeroll on different accounts with the same IP.
Wrong, you can use the same IP, but you have to link your accounts with different mobile numbers or it will get banned. Let's say you have 4 family members and all 4 of them wants to create their own account and work through the same home router. < with a single IP address > then you just register/link each user with their mobile phone numbers.
A lot of people have already done that without any problems. The reason Freebitco.in did this was to stop people from leeching with 1000's of accounts via 1 IP address and emptying the Faucet pool. They do however accommodate people, who use 1 IP address for a limited amount of accounts, but then it has to be linked with mobile phone numbers. ^smile^