I am surprised anyone who has been on here a long time would expect the OP to give an example, we know that would be a 'thread about a thread' as someone has already said.
When I was fairly new I wrote a post about bullying and was shot down in flames, told if I didn't like the heat to get out of the kitchen, that was unkind to a new member. I think we should try to understand the OP and assume it is a post showing genuine dislike.
Some of the comments seem to me to be a bit lacking in understanding. OP didn't say it was today's posts, said they had read it today, somewhat different.
My issue is about those who make a comment which is later disproved and they cannot bring themselves to apologise. One of my posts was deleted because it 'couldn't be verified' so I verified it twice but no apology. I respect anyone who apologises when they realise they are wrong but, if they don't, then I tend to think their future posts are less credible.
Like others I avoid certain people who seem to be unkind for the sake of it. Many of us know who they are.