Why do Muggle-borns go on the run in DH?
I was just wondering, why do Muggle-borns go one the run in DH? I mean in some cases, like in Ted Tonk's case, they have to leave their home and family. But why do they not just set up another life somewhere else rather than be continually on the move. Voldemort's rounding up of Muggle-borns seems to rely on sporadic raids and luck rather than thorough investigation so it would be reasonably easy for a Muggle-born to just set up themselves in a Muggle area, rather than always be on the move.
Is there any reason you can think of as to why this would not have been possible?
I considered the idea that it would mean they would have to stop using magic, because magic seems to be detectable if it occurs in a Muggle area. However surely if a wizard's life depended on it he would be able to stop using magic? Or do you think wizards and witches would get ill/ be personally affected if they are prevented from using magic?