They're jokes, for the most part. But they hurt a product's rating.
For example, a Christmas tree ornament from FunnyShirts.org promoting Trump's iconic slogan has a two-star rating out of a possible five, thanks to 90 one-star reviews left during the preceding five days. Some comments with respect to the president-elect are far too offensive for print.
Here are some of the safer nonreviews:
"As soon as I hung it on my tree, it started insulting all the other ornaments," wrote one critic.
"My Christmas tree is leaning far, far to the right, to the point of tipping over and self-destructing," according to another commenter.
And yet another added, "Turns orange the higher you put it on the tree."
None of the 119 reviews is marked "verified purchase," meaning Amazon can't confirm that the person writing the review bought the item on the site. Unverified reviews are still posted because Amazon assumes that reviews of items purchased elsewhere have value to consumers.
"We feel like we make a great product, so it's frustrating to have negative reviews when people clearly haven't even seen the item," said Jeff Benzenberg, director of new development at eRetailing, which owns FunnyShirts.org.
Benzenberg isn't asking that the reviews be removed — he even finds some of them funny — but he wants Amazon to somehow note that they may be left by pranksters. More importantly, he'd like to see the two-star overall rating removed from the results page.
It's not all bad for Trump gear. Fans shopping for the president-elect's signature red hat or a campaign T-shirt will still find plenty of positive reviews.
An Amazon representative didn't immediately respond to a request for comment.
The Cyber Monday pranks represent just another chapter in the bizarre relationship between Trump and the e-commerce giant.
Trump took several jabs at Amazon while on the campaign trail, claiming that the company is a monopoly, doesn't pay its fair share of taxes and would have "such problems" in a Trump presidency. He also said that CEO Jeff Bezos, who owns The Washington Post, uses losses from the newspaper to create a tax shelter for Amazon.
Bezos tweeted a reply to Trump in December, telling the then-candidate that he'd save him a seat on his rocket to space.
Following Trump's victory, Bezos sent a congratulatory tweet and offered the president-elect his "most open mind."
Critics on Amazon are taking a different approach.
Among the holiday items the Trump store is selling on Amazon is a red Christmas ornament emblazoned with the Make America Great Again slogan. The product has a rating of 1.5 stars, including 81 one-star reviews left during the past six days.
One reviewer even found a way to reference Trump's criticism of how Vice President-elect Mike Pence was treated at a recent Broadway performance of "Hamilton."
"This ornament keeps tweeting at 3 a.m., demanding apologies from the casts of various Broadway musicals."