Create a yes-no survey on using the death penalty to punish adultery.
Overflow the more militantly sexist subreddits with sob stories of men getting cheated on for a few months on high-karma accounts (establishing a narrative).
Note down the progress of how much more hateful the comments on those posts are becoming.
As the "hate" is tending to peak, release the survey you constructed at the very beginning, but put it behind a lot of window dressing such as "Given more than enough circumstantial evidence of the committing of adultery, should a perpetrator be considered for a life sentence/death penalty?"
I guarantee you that, due to the anonymity in a survey, you will get a higher average of responses in favor of it, and it will be far greater than "10 Americans". This data, although the majority of users must've said "no" can be twisted to fit an anti-American narrative even further. For example, let's say the survey yielded a 10% yes and a 90% no. The biased news channel could take the survey results from only the subreddits yielding the highest number of "yes"'s (which, let's say is 20%) and ignore the rest of the data. After that, let's say the news channel drops the window dressing of the original question when choosing to report it. What you will see on the news will now appear like this:
"BREAKING NEWS
In a recently conducted study, 20% of American Redditors have said "yes" to punishing adultery with the death penalty. More on that shortly."
Now you read that and you might think "Nah, a news channel can't twist a survey that much. Must be illegal.". And I tell you that first of all, it isn't illegal (freedom of the press), and also I will point you to Fox News as a more famous example of an outrageously inaccurate American news outlet, although there are many others as well.
This is how you get over 10 Americans to agree that adultery should be punishable by death, and this is also why you will never see anything positive about Muslims on western news.