Inside the MBTA kiosk leading to the concourse under Causeway Street for the North Station Green/Orange Line subway. Observed at about 8:30 am.
There was one outside the Pru mall entrance on Boylston this morning, too. 11am.
There was one in front of Faneuil Hall on Wed...not there yesterday or today in the rain, however.
Do they need some kind of permit/permission to be inside/on MBTA property. (I can't imagine waiting for a train with the blasted bell ringing continuously...)