The other side does the same. Here is the story. I have a client - small market research company, covering Russia. I made bilingual website for them. When Ukrainian conflict started, their Russian contact form was heavily abused by some pro-Ukrainian trolls, posting physical threats to company employees (UK-based, by the way). I coded check against vocabulary, but it appeared, trolls were restlessly trying to bypass my hidden rules for business conversation. It took a week of polishing vocabulary rules. And I added math captcha. In the end I won. They even wrote me a give up letter. Their IPs were mostly Polish and French.

UPD: The hosting was US-based. So they were deliberately looking for Russian forms.