How does filtering work in multiplayer?

Currently the following filters are available:

• by score: with this filter enabled, only players within 10% of your score will be shown. So if you have 1000 points, you’ll see only players with at least 900 points and at most 1100 points.
• by subnet: The filtering is done by IP address. Only players with IP addresses from your “virtual neighborhood” are shown (technically speaking it’s a Class-C subnet). This usually means only players from the same building or block, although it depends on your Internet provider. This mode is perfect when you want to play with a coworker or at home with another person in the same house.
• by country: only players determined to be in the same country as you are shown. This method may not be always available. Players who’ve just created accounts may not have their country determined yet.

We should mention that your location (both the IP and the country) are safe. Another player cannot learn your location.