How Frustrated Strings Would Pull the Black Holes from the Centers of   Galaxies
  Recently Pen and Spergel (1997) have shown that a universe whose energy density is dominated by a frustrated network of non-Abelian TeV-scale cosmic strings could account for a broad class of cosmological observations. In this paper we consider the effects of such a string network on the massive black holes widely believed to inhabit the centers of many galaxies. As these black holes traverse the universe together with their host galaxies, they would intersect a large number of string segments. We argue that such segments would become stuck to the black hole, and be stretched by the hole's motion. Stretching the strings would cause significant deceleration of the black holes. Although the black holes would probably not be removed from the galaxies completely, they would be noticeably displaced from the galactic center of mass -- by at least 5kpc. This displacement seems to be is contradiction to the observational evidence. 
Glenn D. Starkman and Dejan B. Stojkovic