Seems some bot has taken over... Hastags like foodstr, introductions and others are being spammed repeatedly. Not sure how I would block said bots?
Discussion
If you use a client that implements web of trust you would never see the bot spam because you are not following the npubs and who you follow is not following those npubs.
Second option would be to look at the relays the bot posts to and leave those relays.
You can block words and hashtags with the security tab under your profile.