11.   The issue of grandparents seeking custody or visitation rights with grandchildren has become a thorny one in court.

12.   But the issue is a thorny one.

13.   The constitutional issue has been a thorny one in negotiations carried out by the London and Dublin governments aimed at drafting a framework for political dialogue in Northern Ireland.

14.   The issue has been a thorny one for the Sino-British joint liaison group on Hong Kong affairs which meets regularly here and in Beijing.