I believe there is a " no solicitation " ordanance for Bluff Park or at least some parts of Bluff Park. maybe someone can verify that.

From the City of Hoover:
 
Information provided by Revenue Department    
 
ADT is classified as a general contractor and issued a General Business License that allows them to go door to door as along as they follow business hours for visitation -8 PM being the latest. ADT employees are required to carry a “copy” of the business license and ID, but do not have to show you the BL unless you ask to see it.
 
They are not allowed to harass a homeowner into purchasing their product and if this occurs you are to call the police.

They are legit. We are getting ADT system installed today (I think, unless I change my mind). I questioned if they were real, and Rick showed me his badge. I had to fill out mounds of paperwork too. Rick had on ADT shirt and had large folder with ADT logo on it. Also smells of smoke!!
 
I did think they could have been more professional though.

They were on my street at almost 6 pm last night - it was dark - and was not about to open the door to a stranger.  He tucked a flyer in handle.
Who comes at the dinner hour, in the dark?

Just a thought.    
I had a security system installed years ago (not ADT) in a previous home and when I sold my home I called to cancel my service.  They told me I had to transfer the service to the new owner and they had to pay for it.  If they didn't want it I would have to continue to pay -that it was in the contract I signed.  After dragging out my contract and reading the very fine print..I found the salesperson did not mark the block that obligated me to do this.  So, I called and told them what my contract said.  They then had a collection agency and attorney and so on and so on call me for two months.    
Before you sign make sure you can cancel it and that you are not required to transfer that service to new owners.  Find out if you pay a penalty for canceling the service early because of financial problems or other reasons.  Ask about non-emergency alarm set offs - do you have to pay extra.  How many years are you obligated to pay for monitoring. These were things I failed to ask about, but should have. I found out the salesperson (door to door ) that took my order no longer worked for the company and that she did not mark all their required blocks that made the contract binding.   I liked my security system when I had it - other than setting it off every time I cooked or forgetting to reset it when I came home.  I was on first name basis with the beat cop and fire dept.
Like I said.. just a thought.