Of course, the 53-year-old actor took the opportunity to accomplish an epic "photobomb."
"Apparently he jogged up, shouted 'PHOTOBOMB!' and then ran off laughing," said the woman's friend.
A dicey move for someone to yell "bomb" while running in Boston, but according to Gawker, Spacey is no serious threat.
Actually, the reason for his visit was to meet with those affected by the Boston Marathon bombing.