That should read: "burying scraps in Sicilian soil"
The messages never travel outside of the country, which may bolster a case that no other country may have jurisdiction in helping to track down the mafia members.
Recent Intel leaks have shown us that every government in the world has their fingers tapping all of the telecom links in the world. When we talk about using farm land as a messaging platform, the playing field is a bit more even.
The government doesn't have cameras hiding under every rock, or soldiers posted every 5 feet across the land. Imaging satellites perhaps may not be able to be tasked full-time for years to monitor all of Sicily to the required resolution for the purposes of finding one man, yet.
Balled-up pieces of paper are very much off-the-grid.