Hey folks: don't snitch tag.
If I want to hashtag my own posts, I know how hashtags work, I'll do that on my own.
If I have conspicuously not added hashtags to a post, it's because I do not want the trouble, hassle and trolling that comes with certain tags.
Do not put hashtags in your comments on my posts (or ideally anyone's, but I only speak for myself).
Hashtags drive discoverability. Leave other people in charge of their own visibility. It's a safety issue. 1/2