I was looking at another user's profile (not mine!) and noticed that the account was suspended. The exact text reads:
This account is temporarily suspended for voting irregularities. The suspension period ends in 7 days.
Now I know what happens when someone is suspended, but I'm a bit unsure about the 'voting irregularities' part. I've read a few other discussions here on meta, such as Please don't misuse the voting system
How can one vote irregularly?*
*Not that I'm looking for a suspension, I just want to know what kind of voting behaviour to avoid.