On Khyber, I keep my capped FVS on anon. I mean, ok yeah, it only takes a few seconds to type "/r No thanks.", but when you are constantly getting tells, it gets annoying.
Not only that, but some tells were from people I had run with before, and they knew I was female and thought they could cajole me into healing for them, and thus would not take no for answer.
Sometimes I'd get tells that were just something like "Hard Vod?" Maybe it's because I'm a girl, but I like being asked nicely. "Would you mind healing this Vod on Hard?" is much more likely to get a yes out of me. And it doesn't take any longer to type than the "/r No thanks" that was previously mentioned.
As it is now, I mostly just heal for my guild and avoid pugs at all, spending most of my time on my melee characters.