We only have google adsense ads. So they should only link to legitimate sites. Especially if you run FireFox. FF gives you a warning if you are about to surf into a nefarious web page.
Yes, the ad revenue is spent for the web hosting on GoDaddy. We have warnings from them quite often that we need upgrade our "resources". I think this only occurs when someone (from Russia..?) decides to go on a downloading spree.
All of the old Yahoo groups files, photos, and messages are on this forum...
I used to have a free antivirus app on my Android phone...