I checked on 11/12 and 11/13 and saw that the bicycle is no longer chained to the street sign. For future reference, I have included the pertinent City of Gainesville ordinance regarding the parking of bicycles.

ARTICLE V. - BICYCLES
Sec. 26-188. - Parking.
(a)
Any person may park a bicycle on a sidewalk, provided it does not impede the normal and reasonable movement of pedestrians or other traffic, unless prohibited or restricted by an official traffic-control device.
(b)
Any person may park near, and secure a bicycle to, any publicly owned pole or post for a period of not more than 72 consecutive hours, unless an official traffic-control device or any applicable law or ordinance prohibits parking or securing bicycles at that location.
(c)
A person shall not secure a bicycle to any fire hydrant or police or fire call box or park a bicycle in a location that blocks or obstructs any building entrance or exit, ramp, breezeway or loading dock. A person shall not secure a bicycle to any tree in such a manner that the tree is damaged.
(d)
A person shall not park a bicycle in such a manner as to obstruct the movement of any other legally parked vehicle.