Concerns over unattended teenagers have rumbled for years, and sparked anew last summer when nine were arrested at White Marsh Mall in Baltimore County in an incident involving more than 60 young people. The unease was kindled again in March when police said fights broke out among a group of about 300 teens, nine of whom were arrested, at an event at Eastpoint Mall. And more than two dozen minors were charged with disorderly conduct on Easter after a carnival at Eastpoint was canceled unexpectedly.