When it happened to me, I called the police to scare the guy a little and then I used physical measures (locks) to keep him out until he was evicted.

I feel badly for this man, his family and the trauma the agent was put through but I don't think it's enough to warrant taking absurd measures when you're being sufficiently cautious already.

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Don't measure in regards to reward... measure in regards to risk.

I don't remember what state he was in but in my state (Which is pretty stringent) all that I am required to do is disclose to the buyer (if I am buying it myself) that I am a realtor. 

And 36 Other Key Financial Measures

In theory the meter would go between the boiler and the thermostat and would possibly measure the amount of time water is circulating?

She will come out for free to measure and give layouts.

"Measure twice, cut once"By that I mean, do you due diligence.  

I will be the first to admit that perhaps it is not them getting lazy but me getting stringent.