  Telegram is one of the most popular instant messaging apps in today's digital
age. In addition to providing a private messaging service, Telegram, with its
channels, represents a valid medium for rapidly broadcasting content to a large
audience (COVID-19 announcements), but, unfortunately, also for disseminating
radical ideologies and coordinating attacks (Capitol Hill riot). This paper
presents the TGDataset, a new dataset that includes 120,979 Telegram channels
and over 400 million messages, making it the largest collection of Telegram
channels to the best of our knowledge. After a brief introduction to the data
collection process, we analyze the languages spoken within our dataset and the
topic covered by English channels. Finally, we discuss some use cases in which
our dataset can be extremely useful to understand better the Telegram
ecosystem, as well as to study the diffusion of questionable news. In addition
to the raw dataset, we released the scripts we used to analyze the dataset and
the list of channels belonging to the network of a new conspiracy theory called
Sabmyk.
