Image copyright Paul Davids Image caption Paul Davids can normally be found on YouTube explaining guitar techniques
Paul Davids thought he had seen it all when it came to YouTube's copyright protection system.
The Dutch YouTuber's most popular videos include him playing famous guitar riffs, comparing different instruments and teaching various guitar skills and techniques.
"Just like probably all the music YouTubers out there," he explained in a video to his 625,000 subscribers, "once in a while I get an email stating I'm infringing on someone's copyrighted material."
Paul had been contacted by YouTube to advise him that one of his videos had been flagged for copyright infringement, but in his own words, "this was a little different".
The copyright he had apparently infringed upon was his own.
"It said what song I was infringing on, and what I found was quite shocking," said Paul.
"Someone took my track, added vocals and guitar to make their own track, and uploaded it to YouTube, but I got the copyright infringement notice!"
Paul had been accused of plagiarising his own music - and worse, all the money that video was earning would now be directed towards the person who copied his content.
How do people make money from YouTube videos?
Image copyright Paul Davids Image caption Paul's most popular video with almost eight million views features him playing famous guitar riffs
A video can be "monetised" if a YouTube channel has at least 1,000 subscribers, and more than 4,000 hours of their content has been watched in the past 12 months
So long as the channel fits these requirements, users can apply to join the YouTube Partner Programme and have adverts attached to their videos
Often YouTubers will make money in other ways, through working with brands, merchandising and crowdfunding
Despite being faced with a claim of copyright infringement and demonetisation, Paul remained calm.
"I looked up the guy on Facebook," he said. "I wrote him a message.
"I asked: 'Are you aware that you used one of my tracks to publish as your own track? Let me know'.
"A few hours later I got a response. 'Hey, I don't know', he said. 'I did download a couple of guitar licks somewhere off YouTube. Would you consider letting me still use this?'
"I wrote him back saying, 'You can't just rip a track off YouTube and then claim it is your own. Did you know I got a copyright notice from YouTube about that track? Claiming that I was infringing on your track?'
"That's quite odd, since I wrote and recorded it."
Image copyright Paul Davids Image caption Paul also makes a series of popular videos where he teaches people how to play different riffs
In the end, Paul decided to do the nicest thing he could think of - he let the copycat keep using his song.
"It's not like he will make tons of money with it," Paul said. "It's OK. It probably happens all the time."
The BBC has approached YouTube for comment.
This is not the first time there has been such an issue with YouTube's copyright systems.
In 2015, Mitch Martinez had monetisation removed from a video after Sony filed a copyright claim against the video he licensed them.
And in 2010, pop artist Justin Bieber was caught up in a row with the platform when they temporarily would not allow him to upload his new song - because someone else had uploaded it first.
Image copyright Steven Bridges Image caption Steven Bridges has had his own share of issues with Content ID on YouTube
At the heart of the controversy is YouTube's Content ID system - the automatic process which decides whether a video contains copyright infringement.
Steven Bridges, a magician with more than 178,000 subscribers on YouTube, tells the BBC how this might have happened.
"Content ID is in place to make sure people don't use content without permission of the original creator," Steven explained.
"YouTube's systems automatically scan videos and detect if they've got, for example, a pop song in the background.
"If the video does, then the owner of the song could be notified, and they can choose whether they want the video to be left online, or whether they want to monetise the video themselves.
"It's a great system but it has its faults. For example, sometimes content can be wrongly demonetised or taken down. Certain companies can 'claim' videos if they find copyrighted material in them, regardless of whether YouTube's Content ID detected it.
"The creator has to go through an appeal process if they think it's been unjustly claimed.
By Tom Gerken, BBC UGC & Social News team
Killboypowerhed on July 6th, 2018 at 17:30 UTC »
Reminds me of the time Family Guy used a clip from a YouTube video and then the original video got a DMCA from Fox
thudly on July 6th, 2018 at 15:56 UTC »
I pretty much gave up on YouTube as a source of revenue for my original works. I wrote a computer program that generates procedural music. I uploaded one of the songs for any computer science/proc gen enthusiasts who might be interested. It wasn't a very good song, as songs go, but it was interesting from a computer science perspective.
It was my original content, so I clicked the monetize button. I wasn't expecting to get rich or anything. But over time, maybe I'll make enough to buy a coffee or something.
Nope, YouTube says. Before I can monetize it, I have to prove that I own the content. How exactly do I do that? I had no idea, and they were no help. I sent a help request, like a drop of water into the sea and got a canned response about how they "take all my concerns seriously" and they'd get back to me as soon as possible. Years later, I still haven't heard back.
I never did get that coffee.
Recently, though, I sent in a demo of a song I wrote to a producer. He liked it and wants to get me into the studio. Exciting news. But I'll be damned if I'm going waste time posting the thing on YouTube. I might as well just save myself the trouble and get somebody to kick me in the nuts now.
RudeTurnip on July 6th, 2018 at 15:25 UTC »
I've had this happen because a video I created, and a song that someone wrote several years later, both had a snippet of the same public domain audio. I disputed the claim of course, and Youtube un-fucked it.