Zillow, Trulia WARNING!

I’ve commented about the deception these web sites create before. Case in point; Had a buyer contact an agent on one of my listings thinking they were the listing agent. During showing buyer quickly realized this agent knew nothing about the property. Post showing, with no relationship between buyer and agent, no follow up, no offer no feedback to me on showing by agent. Two weeks later I have accepted offer by other buyer, sellers run into previous buyer who wants the property, but it’s too late. Who are you using as your Realtor? Do you know anything about them?