Plagiarism check on Zulipchat

Stream: new members

[Yagub Aliyev]

Does anyone now if available plagiarism checkers can scan also Zulipchat? I ask because I had bad experience with https://rextester.com/ where I put on a wall some of my codes which I then used in my papers. I later had hard time explaining my publisher that these are my own codes not a plagiarism :-)

[Johan Commelin]

Most streams are world-readable. So in principle they can be scraped. I have no idea whether this actually happens