Because no photo or description of the posters was provided, it is possible that these posters may have been legal when this was posted. Please see bylaw- 693-31: http://www.toronto.ca/legdocs/municode/1184_693.pdf

"693-31. Community posters on utility poles.
A. Despite § 693-29A, persons, charities, religious organizations, community organizations and schools may erect, attach, place or display, or cause or permit to be erected, attached, placed or displayed community posters on utility poles as permitted under Subsection B.
B. A community poster may be placed on a utility pole located on a boulevard if:
(1) The community poster is no more than 22 centimetres by 28 centimetres in size;
(2) The community poster consists only of lightweight cardboard or paper;
(3) The community poster is securely attached flush to the surface of the utility pole using staples or removable tape and no other method of affixing the poster to the utility pole is used;
(4) The community poster is placed no higher than two metres above the ground;
(5) The community poster includes the date of posting on the front of the poster;
(6) The community poster is displayed for not more than the earlier of:
(a) Thirty days; or
(b) Five days after the end of the advertised event, if any;
(7) Not more than one community poster conveying essentially identical information is posted on the kiosk;
(8) The community poster faces towards the property fronting on the highway and away from the portion of the highway ordinarily used by vehicles; and
(9) The community poster includes valid contact information for at least one owner of the poster."

As it possible that they were permitted, and as they are also doubtless gone as this issue is five years stale, I will close this off now.