I did something for the first time ever on any SE site today, and that was not reject an edit from an anonymous user. (I am able to open review queues on 5 SE sites). This particular edit was nothing but helpful, but whomever offered it is listed as an anonymous user. My experience for the last two years on edit suggestions from anonymous users is that they are either vandalism or just bad.
Can someone explain why an anonymous user, who has not signed up for the SE site, is allowed to edit other users' posts? It seems to me an invitation to vandalism and against the "high signal to noise ratio" premise of each SE site.
Is there a consensus/policy on how to handle these during reviews?
As this is a site still in beta, and my search of our meta found no useful links to meta questions on anonymous users editing content here, I'd be interested in what the consensus is on History.SE regarding how to deal with what I see as intrusions into the activity of the people who signed up for this site by those with no stake in this site's health.
There does not seem to be a hard and fast policy on this for SE writ large.