Grief alerts can be seen by players.

[Former user]

Not sure as to exactities, but when I logged in as my non mod account, when I broke stuff I could see g alerts of MY breakages just like staff.

[Riot]

Duplicate of http://code.minecraftonline.com/griefalert/issue/10/some-players-can-see-grief-alerts-and-sign.

[Riot]

Might be helpful if you could mention what account that is, and exactly what you saw / can see, with screenshots, though