  In this work we carry out an exploratory analysis of online conversations on
the Italian Facebook during the recent COVID-19 pandemic. We analyze the
circulation of controversial topics associated with the origin of the virus,
which involve popular targets of misinformation, such as migrants and 5G
technology. We collected over 1.5 M posts in Italian language and related to
COVID-19, shared by nearly 80k public pages and groups for a period of four
months since January 2020. Overall, we find that potentially harmful content
shared by unreliable sources is substantially negligible compared to
traditional news websites, and that discussions over controversial topics has a
limited engagement w.r.t to the pandemic in general. Besides, we highlight a
"small-worldness" effect in the URL sharing diffusion network, indicating that
users navigating through a limited set of pages could reach almost the entire
pool of shared content related to the pandemic, thus being easily exposed to
harmful propaganda as well as to verified information on the virus.
