Apparently, some Alexa-enabled devices have started laughing in a disturbing manner at their owners. There have been reports made of unrequested creepy chortles issuing from smart speakers and Amazon devices by a number of users, who cannot understand why their personal assistant has suddenly become so sinister. Amazon is currently working on a fix for this disquieting issue.
https://www.notebookcheck.net/Unexplained-Alexa-laughter-is-freaking-people-out.287640.0.html