That was the key question Tuesday from Nicolo Milioto, a Sicilian-born ex-businessman who knew mob patriarch Nick Rizzuto Sr. for 40 years but told a public inquiry he had no idea what Rizzuto did for a living.
The ex-paving specialist, nicknamed "Mr. Sidewalk", accused by another witness as being a Mafia middleman, spent much of the morning admitting he knew key members of the Rizzuto crime family, including Nick Rizzuto Sr. and his son Vito.
He even recalled that the elder Rizzuto lent him up to $20,000 for his daughter's wedding in the late 1990s.
But it was far more difficult for inquiry counsel Sonia Lebel to get the elderly witness to define the Rizutto family's organized crime links.
"What's the Mafia?" he asked. "I can't explain it to you, I don't know that. ... Is it someone who kills? Is it someone who steals? Is it someone who sells drugs? I don't know."