Depends a lot on the anemone. I have 2 x Haddoni Carpets in my tank and accept that they may kill fish at some point. So far none of my corals seem to be bothered by them. They actually bump up to my hammers and duncans, and so far everyone seems to be getting along.
Many reefers keep Mags, Gigs, Haddoni, RBTA, Rock Flowers, etc in reef tanks will little to no issues.