I do not like plagiarism, and I do not often mention it. When an Author "Repost" content of their own from a different site, the only way we have to know if it is theirs is for them to state it or to give a source reference for it. I checked, found it elsewhere, and chose not to comment or vote on it, at least I did not use the plagiarism term when I found it elsewhere. I normally do.
And you are quite right no post can be fore everyone. Spreading the message is a good thing, I would urge you to ensure you cross link your postings so there is no doubt about it being your content.
This is a contest/program to recognize people and what they are doing. I will leave you with this thought, How would you feel if you found your post being used and claimed by another person. If I had not found a copy of your post elsewhere, I would have made a comment and voted on it whether I got anything out of it or not, because the contest is about recognizing the contributions from others, not my own personal taste.
I will never vote, and have removed votes, and muted people, who steal and claim other people's content. And I will not apologize for my stanze on that point.