I also am adding my voice to all those Airbnb hosts who want a way to block guests. I may have no choice but to turn off Instant Booking if this feature is not added soon. I am a new host and overall I have had wonderful experiences thus far; however, this is the review I just left on a couple who stayed night before last - They, of course, gave me a great 5 star review. Now, really, wouldn't anyone in their right mind want a way to block these people? BTW, the 'stains' I am referring to here were BLOOD. One or both of them were hacking and coughing all night and morning and I suspect one of them has tuberculosis or similar. And while we are on the subject, what does Airbnb do to educate hosts on how to handle bodily fluids that may contain infectious pathogens / contaminants (like Hep C, AIDS, etc) or from guests who are active with tuberculosis yet decide to check in to our homes as if we are a hotel equipped to sanitize and sterilize everything? Some more education seems warranted here. Here's the review I just left, which I forwarded to Airbnb. I also called them last night to share what happened, and sent pictures. My beautiful suite looked like a scene from Hitchcock's 'Psycho': "William and Jane were guests on June 14th, 2017. They were very pleasant but may be better suited to stay in environments that have a team of professional cleaners who can quickly handle tough jobs. Although I'm sure it was unintentional, my beautiful, brand new suite (with new everything, including designer paint) was left in such a manner that it took me and my partner two hours longer to clean and sterilize the suite for the next guests than it usually does due to multiple stains on linens and robes, in the bathroom sink, shower, floors, and walls - All which required careful (gloved) handling and lots of bleach. Also, crumbs and coffee stains were left on the bedroom side-tables even though I provide 6 coasters to use, and crumbs were on the bedroom floor. Also, coffee grounds were left all over the sink and elsewhere in the kitchenette and in the cups, and all over the coffee maker. Although the dishes were done, I had to rewash all of the dishes and utensils and sterilize them in hot water and bleach due to the stains I found in the sink and on the kitchenette counter. It was a very surprising and upsetting experience, one I did not expect to have to face while hosting on Airbnb."