  Online social media enables mass-level, transparent, and democratized
discussion on numerous socio-political issues. Due to such openness, these
platforms often endure manipulation and misinformation - leading to negative
impacts. To prevent such harmful activities, platform moderators employ
countermeasures to safeguard against actors violating their rules. However, the
correlation between publicly outlined policies and employed action is less
clear to general people. In this work, we examine violations and subsequent
moderation related to the 2020 U.S. President Election discussion on Twitter, a
popular micro-blogging site. We focus on quantifying plausible reasons for the
suspension, drawing on Twitter's rules and policies by identifying suspended
users (Case) and comparing their activities and properties with (yet)
non-suspended (Control) users. Using a dataset of 240M election-related tweets
made by 21M unique users, we observe that Suspended users violate Twitter's
rules at a higher rate (statistically significant) than Control users across
all the considered aspects - hate speech, offensiveness, spamming, and civic
integrity. Moreover, through the lens of Twitter's suspension mechanism, we
qualitatively examine the targeted topics for manipulation.
