The post from the Bayou Renaissance Man resonated with a lot of readers particularly this line:
They, unknown to me, told half-a-dozen other families to come too - "He's a good guy, I'm sure he won't mind!"
I think the best answer is to be very up-front with people (if any) you invite to share your space.
"If you show up with an uninvited guest then neither of you are welcome. You can find someplace else to squat."
"If somebody shows up later and claims you invited them...and you admit you did...you are both out on the street."
"I am a total, cast-iron prick when it comes to protecting those closest to me. I will not let ANYBODY jeopardize that...not my cousin or my neighbor or even my son or daughter."
"Never make the mistake of thinking I am a 'nice guy' or that your opinion of me matters even the least, little bit."
And be perfectly clear in your head that you WILL toss your son or daughter out in the street without hesitation if they are the ones drilling holes in the bottom of the life-boat.