Although it has been illegal all along to post signs on utility poles, everyone still does it because nobody is enforcing it.  According to state law, without first obtaining permission(which I am sure no one has done), there is a $250 per incidence fine and the violator is responsible for any cost to repair.  See law here: 

http://www.rilin.state.ri.us/statutes/title11/11-35/11-35-28.htm

Now, Coventry, RI has passed an ordinance to prohibit posting on poles and fines will range from $100-$250.  It sounds as though they are going to try to enforce it.  It is sad that people who lose pets can no longer post those notices because I think that is an effective way to find a pet.  Here is the Providence Journal article:

http://www.projo.com/ri/coventry/content/WB_coventry_council_12-11-07_PJ8740L_v7.28ba484.html

I am ecstatic.  Although I don't live in Coventry, I drive through it everyday and I cringe when I see these poles that have 3 or more signs on them.  It makes everything look messy and congested.  At election time it is even worse with all the signs on lawns adding to the clutter.  Luckily, I live in a town that does not have lawn political signs.  I am relieved to be near home at those times just to be away from the mess.  It especially bugs me when my fellow agents can't be bothered to remove the signs after they have sold the house.  Sure, other citizens leave up their yard sale signs, etc, but they aren't being paid to do a job.  Sometimes we seem to forget about these little details after the sale is over.  It's funny when I go over to list a house and the last agent's sign is in a corner in the garage because they never bothered to pick it up.

I do not post signs on poles already.  I just think as Realtors® we are supposed to follow all laws.  How can we then go and blatantly ignore them and put a sign on a pole?  I have, on occasion put a sign up at the end of the road, but only with the permission of the owner of the property.  When people ask me if they can have a sign at the end of the street, I just inform them that putting them on the pole is illegal and if they get permission from their neighbor, I'll be happy to place one there.