On the 111 Matatu from Prestige Plaza, 3 young men got an almost full Matatu. One of the men sat in front of me and the other two behind me. As we drove a bit up Ngong Rd. the one behind leaned over me to his friend in the seat ahead and said, hey, put on your seat belt there's a police roadblock ahead. This is a scam to get people to start looking for their belts so that the robbers can grab phones, wallets, etc. I had heard this scam before so I didn't react and did not have anything stolen. I got off at the Adams Stage to avoid further incident.