Two days ago, the Graham Avenue C-Town issued a community alert on their tumblr page (yes, they have a tumblr), saying:
Today we were alerted by the police that somebody is sexually assaulting women as they walk up the stairways off the Graham Ave & Grand St L train stops. 3 women have been attacked to date. The attack on Graham Ave happened late at night (3-5 AM).
Unfortunately, further details were not provided and a cursory Google search yields nothing. So if you have information on these incidents, please contact NYPD.
Stay safe out there, friends!