During the November 2007 Critical Mass bicycle activists in São Paulo installed their first ghost bike at the spot that an unnamed rider was killed by a bus in August 2006. This was one of many actions intended to call attention to the dangerous cycling conditions in São Paulo.

These included mapping the 84 fatal cyclist crashes in 2006 in and around São Paulo, stenciling and other street art. See the photos here. As a result one elected official pledged to create 50km more bike lanes in the city. As reported in this article

For more information (in Portuguese) about these actions see:
Pinha Livre
apocalipse motorizado