Each account participates in a lottery event after a seven-day check-in period; this is true for at least the four accounts I've registered so far.
There are two ways to get banned: being reported by other players or having data anomalies detected by the system.
I'm usually very careful not to appear at the top of the leaderboard. I played for about twenty-one days.
During the first lottery event (day eight), I didn't notice the free lottery feature and nothing seemed wrong. During the second lottery event (day fifteen), I started using the free lottery, and after the second event ended, I couldn't log in anymore; it showed my data was abnormal.
If it really is a problem with the free lottery, then the Ark and Vanguard event passes become extremely important.