Got Grifters?

Am I the only one who gets solicitors coming to the door at least once a week?  They drive up the dirt driveway in big shiny pick up trucks.  My dog barks.  And barks.  And barks.  Grifters never ring the doorbell.  They just get out of their trucks, usually with someone remaining in the passenger seat, and walk around the perimeter of the house.  When I step outside and ask, "Who's there?" they say they notice I need chimney repairs, my driveway paved, or roof work.  They offer a free estimate.  Apparently roof work and driveway repairs are big grifter business.  I would not need driveway repairs if those big grifter pickup trucks were not coming up and down my driveway, wearing it down.

I have a "NO TRESPASSING" sign.  They claim they haven't seen it.  They always apologize when I tell them they are trespassing.  They are generally quite polite.  They sometimes have out-of-state plates.  They leave when I say I have someone who does my repairs.  Maybe I should suggest the grifters go to the local police station or sheriff's department and inquire whether they need roof or driveway repairs.

I bought a "NO SOLICITORS" sign and hung it at the bottom of the driveway, hoping to stop the grifters before they drive tonnage of pickup truck up my road.  They claim not to have seen that sign either.  It is red!  I am frustrated.  I got two more "NO TRESPASSING" signs and added "NO SOLICITORS" in black permanent marker on one of them. I am looking for the best, in-your-face place to hang the additional signs.

Frankly, I wonder whether these folks are trying to sell home repairs or just casing the area.  Is it just the economy?  Are these just out-of-work guys trying to drum up business and make the payments on their new, shiny pickup trucks?  Or is grifting a highly profitable business that enables one to afford a big, shiny, new truck?  Grifting is a line of work that does not appear to start early in the morning.  They generally arrive late in the morning or after noon.  Don't you want a job where you just show up at a house, mid-day, whenever and wherever you want?  Anyone else got grifters?

4/2/11  Grifter Addendum:  Update regarding how to respond to suspected grifters or other trespassers who come to your homestead to sell you services --
1.  Note the color, make and model of their vehicle.
2.  Note the license plate.   Are the plates out-of-state?  Remember the license number - write it.
3.  Is there a business name on the truck? 
4.  Are there any tools or work gear in the truck?
Out-of-state plates, no business name on the truck, and no tools or work gear in the truck bed may be indicate grifters.  If you observe suspicious activity by strangers on your property, give the information to your local police or sheriff's office.