Neil the roving UHub photographer couldn't rove much past Mr. Roboto here yesterday. He dug up the background on Tobor:

Allied Universal, a leading facility services company and the largest security force in North America, has partnered with Boston Properties, to pilot a robot patrol program at the Prudential Center from May to August 2017. Technically called an Autonomous Data Machine, the Knightscope K5 model security robot will support the Prudential Center’s existing security team with a patrol route over the next three months. Prudential Center will be one of the first in Boston to introduce this sophisticated technology to enhance its current security program. The security robot is scheduled to start patrols within the Prudential Center retail area only on Tuesday, May 16.