I find them helpful at best and harmless at worst.
And this is of course just my opinion, but I find the idea of putting someone on moderation because they haven't removed it absolutely abhorrent. Group members have enough legitimate things to worry about paying attention to in group guidelines. I would never dream of moderating someone for something like this, nor caring or complaining about anyone's typos (or punctuation errors - which, ironically, abounded in one of the complaining messages in this very thread).
Who cares? People should be civilized and adhere to important group guidelines. Groups.io should remove offensive "Avast antivirus" ads and the like. Members should be free to set their own signatures as they see fit, including whether or not they want to include the (sometimes helpful) fact that they're responding from an iPhone.
I'm done with this.
Messages are the sole opinion of the author. Especially the fishy ones.
I wish I could shut up, but I can't, and I won't. - Desmond Tutu