So I just upload all of my content to istock and am happy to let them reject any of the editorial clips that they want, usually named in the SS format.
But curiously they did not reject any of my Cambodian or Vietnam clips that featured people, groups or people / recognisable faces (some in a mid shot) but they rejected all of my Sydney Australia wide street time lapses as 'maybe' some faces at traffic lights are kind of visible (no logos).
Curiously it does go to show that double standards do exist..
Maybe they think that someone for a poorer country is less likely to sue?

or maybe there are real legal issues that they know.

Actually it is your job as a photographer to research this beforehand, because the court case will go to you not them. You assure the agency that you have checked all legal aspects before you upload. All agencies have that as a fine print. They do use their own legal guidelines, but that doesn�t absolve you from your responsibility.

Umm good point. But as IS does not accept editorial and all content featuring people should come with a release then the decision to accept content is on them, also as they take the majority cut in royalties then liability would be on them.
I recently spoke to a government body in Australia regarding obtaining a release for Uluru and they told me that they are having a hard time getting IS to abide by Australian law, the issue being that it is possible to get a property release for shooting in a national park but every client that uses the media for whatever purpose also needs to apply for a release form the parks and wildlife services independently. All stock sites are not following this legislation and most including IS do not even mention that buyers should do this. If a countries government body can not get IS to follow the law then I have no concerns.

"But as IS does not accept editorial and all content featuring people should come with a release"

I don't think this is correct. istock has accepted photos from me that are editorial (a few of which have even sold!), they do require special formatting, but haven't asked for releases of the people in the photos. I believe they do want property releases though if there are restrictions by the property owners.