I belong to quite a few Yahoo groups, most of them inactive, and lately the site has been pretty flaky, down often, lots of glitches. I have almost never had spam on the groups I am on, they are moderated actively. A couple of the groups I am on have large database files that will be a disaster if they go away for people who have old equipment and need to figure out how to deal with them, run them, and repair them. There are also large photo archives. Apparently it is difficult to impossible to move a Yahoo site to another host while still retaining all the content. They do not make it easy. It will be sad if and when Yahoo groups goes down.