Went through the reviews of some add-on I have installed and noticed that two of them have a lot of fake reviews. They are obvious because it’s either nonsense with a five stars rating or the users registered on the same date they wrote the review. It’s usually also the only review they ever wrote, or they wrote multiple ones for the same add-on.
I reported a few accounts and reviews some days ago, but they’re still there. Mozilla doesn’t seem to care.