peeps are reporting 'i got you' messages:
https://www.reddit.com/r/Bitcoin/comments/13tedzc/should_i_sent_a_dick_pic_back_to_assert_my/
I am not sure how it's related to Coinbase. I saw the email address was [email protected]. But this is the received email. If a user uses their email on the internet, it's not hard for a scammer to collect email information from the internet and use them for their purposes. The email they got is pretty much an old scam. I am surprised these scam attempts still work, and people fall for it. The scammers send the same email to thousands of emails. One Reddit member said the Bitcoin address he received from a scammer to pay; he already got five $400 transactions. This means five people got scammed.
I did not see anyone commenting on whether they are Coinbase users.
Life is a series of IQ tests.