Might be worth noting that /var/log/btmp is used for console login. If you're interested in failed ssh attempts to login you may want to look in the /var/log/auth.log file as that I believe is the default under Debian and Debian-like systems.
Checkout Mapzen: https://mapzen.com/
They're coming out of stealth mode and have some great ideas and some experienced folk from Google and Mapquest.
Might be worth noting that /var/log/btmp is used for console login. If you're interested in failed ssh attempts to login you may want to look in the /var/log/auth.log file as that I believe is the default under Debian and Debian-like systems.