How to confront a joke thief

A comic I know told me he thinks someone else is ripping off one of his jokes:

I have had jokes stolen before but this is my signature joke and he is using it as his opening. What would you do? How would you handle it? My videos with that joke are all over internet as early as 2007, what would you do?

Made me think about my own history in this area. I've been on both ends of joke thieving accusations. And it's not fun.

A couple of times I've been approached by comedians who accused me of taking a joke from them. Both times it was via email. Both times it was from a comedian who I had never seen and never heard of. Both times the emails sent were threatening in tone. Both times the accuser assumed guilt before even contacting me. Both times they were 100% wrong. Both times I explained that I 1) had never seen them before and 2) don't steal material.

For one guy, that was enough. He backed off and apologized and I never heard from him again.

For the other guy, this riled him up even more. He pointed out that we shared a bill in 2010 and that he felt I did steal the joke. I told him that I didn't even remember doing that show with him and didn't recall any of his material. And then I sent him clips of me doing the joke in 2009 and 2008. His response to that: "Well, I'll just have to get it on TV first."

(I get why that used to be the litmus test for a disputed joke. Whoever got it on a televised set could claim to "own" it. But that seems a bit old fashioned in the wake of YouTube. If someone can prove they did a joke first on YouTube, shouldn't that give them dibs on it?)

Then there's the "someone else has a bit like that" note that other comics will give you. I've gotten offstage after telling a new joke and had people tell me, "Hey, Robin Williams has a joke like that." Something like that's happened a few times. No harm, no foul. I moved on.

Then a couple of months ago, I was on the other end of all this. I heard a comic do a bit really similar to one of mine. My first reaction: Is he stealing from me? But then I reflected on it a bit. It occurred to me that the premise of the joke wasn't super unique or anything. It's totally possible that someone else could come up with it. And while there definitely were similarities, it wasn't a word for word rip.

Still, I sent him a note about it. It was gentler than the ones I received. I didn't come out of the gate accusing him. I just told him I have an extremely similar bit and that I'd been doing it for a while. He replied he'd also done his version for a while too. I couldn't recall him seeing me perform the joke before (but that's a tough thing to recall).

At that point, we were both willing to chalk it up to parallel thinking. Still sucks though, knowing someone else is doing material similar to yours. So I rarely do the joke anymore. Ideally, I'd rather be doing material that could only come out of my mouth and from my point of view. If someone else can do the same bit, it feels to me like I'm not being unique enough. I try to use it as motivation to write more jokes that are so Ruby that no one else could ever do 'em.

Getting back to the email up top, here's part of my response to that comic:

If you're 100% sure this guy is stealing (i.e. you know he's been able to see your bit before and it's a word for word ripoff), I'd ask him to stop doing it. If you're not 100% sure, I'd start off with a non-confrontational email (or call) and see what he says in response. Tell him you've got the same joke and show him clips of you doing it from years ago. See what he says. Sometimes this stuff is just parallel thinking and both people come up with a similar joke. But if you know he's ripping you off, you have a right to be mad.

FYI, I think the tone can shift if you're positive that someone else is plagiarizing you. Another comic I know faced that. He found out a guy in a different city was doing one of his jokes verbatim onstage. He sent him a nasty email telling him to stop and the guy apologized and pledged not to do it again.

Related: Should you confront a joke thief?