Even for legal things outside of law firms. Around Y2K someone was stealing content from my site. I sent a takedown notice and they told me I had no proof. So

Even for legal things outside of law firms. Around Y2K someone was stealing content from my site. I sent a takedown notice and they told me I had no proof. So I used WayBack Machine, which was newish at the time, to show when it appeared on my site, and when it appeared on theirs. I was able to pinpoint within a week when they had stolen the text, because at the time it was being updated quite regularly. I asked, but didn't receive an answer, why they stole it and then took two weeks to publish it without even trying to hide their tracks. Then I told them I'm writing a publicly accessible article about their theft, complete with the proof I just showed them, and links to the examples on their site, because hey, why not be an awesome example of plagiarism and outright theft in the wild, and how to prove it! They took it down immediately thereafter, and never spoke to me again. I guess they didn't want the opportunity to be my example.