When dealing with no show people I usually end up blocking them. But there are people that I end up giving second chances for many reasons such as 1) decent ratings 2) they sound genuine about missing the meetup 3) Just gut feeling that maybe it really was something unpredictable. So far I only had 2 dealings with "no shows" or those that are trying to pull your leg but eventually meet. However, I did not give them the benefit of a doubt of a rating because they were either very rude or led me on too much to warrant a chance of giving me a bad rating for something that I as a seller should never even put up with. There are really just two things to watch out for. If they message you and never get back to continuing the conversation for about a week, or situations where they sound too uninterested and half-heartedly commit to it with one or two words answers. But in the end no shows 90% of the time reported and blocked.
This comment really strikes home. Just posted on anothers thread here about posting a real picture of yourself and how shady sales and rating disparity with cutesy profile pictures should ring a red flag and proceed with caution. But called out that you dont have to post a "real" picture. But heck, if you post real pic about yourself people are most inclined to trust you. Now it's a different story if you post a picture that looks nothing like you when you meet up with a person that will probably not be the smartest idea.
Now as with community sites like these, harrassment actions are considered when posting clear usernames of other users that may incite harrassment. However, you can blur the username but keep the profile pic of what they have up and post the whole conversation on another site. Users that could put 2 and 2 together without your explicit post that identifying them is not considered to be harrassment more so if it is for the sole purpose of warning other users.