Question: When Jon Snow is captured by the Wildlings in S02E08 of Game of Thrones, the Lord of Bones says

> 
> Why would we need a dead man's bastard?
> 
> 
> 

How did they know that Ned Stark was dead? It seems unlikely that a crow carrying the message would be north of The Wall.

Answer: 
We don't know exactly how they know this, but it isn't impossible. Wildlings trade
with the Night's Watch at Eastwatch-by-the-Sea. So it could be that they heard about it from the Night's Watch.

Remember that Ned was warden of the North. Besides the Night's Watch, Ned would be the main force preventing the Wildling invasion, so it makes sense they would be interested in him.
Mance Rayder, himself, had been to Winterfell, incognito as a traveling minstrel (when King Robert visits at the very beginning of the saga), so the ability to for people and information to move from one side of the Wall to the other is pretty well established. Plus, as a former member of the Night's Watch, he apparently still had some sources/contacts there (which is how he heard of Robert's trip to Winterfell).