No, they usually get killed using a gun of a knife, or maybe poison.
There are several instances of murders supposedly associated with Craigslist, the most famous being that of Julissa Brisman, who was murdered in Boston in 2009. Philipp Markoff was arrested and charged, and police alleged that he met her (and two other women, who were robbed but not killed) through Craigslist.
Markoff ended up committing suicide in jail before he could be tried.
Earlier this year, there was a similar case in San Diego. There have been many others.