And trolls. One of my mudges is the volume of nonsense messages that come in on topical mailing lists. You attend a list due to interest in some topic - say biochar or geoengineering - but trolls spam the lists with a high volume of long off-topic material that is at best only tangentially related to the topic. It's like going to a club to hear real jazz and finding some guy with an accordion playing polka music while some boozy babe galumphs about banging a tambourine. To make it worse, the same cut and paste off topic messages are spammed into multiple lists, so you get the same tripe more than once.