I think it’s pretty safe to say that the majority of us are here to avoid another corporate takeover of our preferred platforms. It would seem to me to be a tad irresponsible to allow Facebook into our space with open arms, allowing them to hoover up our data. I would love to keep using Lemmy.world, but will happily change instances if need be, and I feel many share that sentiment.
It doesn’t seem like tagging on Lemmy is working at the moment, but you could reply to the thread on Mastodon tagging them there, and that would work (only if you tag their Mastodon accounts, lemmy accounts don’t support tagging on Mastodon, as far as I’m aware).