I was never "in", so I didn't really come out. My daughter, who is bi-sexual and Atheist doesn't know how she feels about using the term "coming out" to describe telling people you are Atheist. I think it applies though. She doesn't hide either from anyone, and I don't either, but I guess I don't advertise I'm Atheist. Too many crazies out there. That's why I won't put any Atheist bumper-stickers on my car. I'm afraid of morons. My daughter has a quote by Voltaire on her car that says something like "People who can make you believe absurdities can make you commit attrocities", but I actually think that's not so dangerous because I don't believe most fundies would even get what that means.
No persecution or negative impact job or career as far as I know. I don't put 'atheist' on my CV or applications (unless they ask in the monitoring forms) but I do state my interests, which include secular humanism as well as science, philosophy and skepticism... I think that's cryptic enough that it will go under the radar undetected by most, unless they are inquisitive enough to look it up, in which case good for them, or it'll be not so in your face beacon to the well informed and likeminded comrade.
When I'm touring on my motorbike I have a Darwin fish on my left pannier, an FSM on my right pannier and a pirate fish on my spare fuel can, which is attached to the back of one of my panniers... I also have an FSM patch on my motorcycle jacket, and sometimes I wear the red scarlet A. When I'm camping I have a red FSM flag too, it helps me find my tent when I'm inebriated and it's usually a good signpost to meet-up with friends. So you could say I'm an out atheist - My blog: TheAtheistBiker, clears up any final uncertainties, LOL. So far so good, never been vandalized. The FSM paraphernalia, flag especially, is a great conversation starter because people don't know what it is or what it means.
Never had anything overtly threatening happen. I find most faitheads are a bit creepy to be honest... but I find that most people, especially work colleagues, are generally very surprised and actually quite interested as they usually have never met an out atheist let alone a vocal one. I do have friends of faith but I have also lost friends and acquaintances, of faith and none, from Facebook. Although, if I'm honest I didn't notice they were gone until I went to find them in my friend list. So no big loss.
Anyway, I have lost one friend on facebook who was a best bud in real life, (not 100% sure yet how it's impacted in our real life friendship as we haven't spoke in a while but that's reasonably normal). The weird thing is that unless he was a secret friend of Jesus, he was largely a non-believer as far as I knew... and he was either too stubborn, or apparently too stupid, to just hide my FB posts and links if he was fed up with seeing them on my own wall. Indeed, he was the only person whose friendship I would consider a loss, but if friends can't accept you for what you are, especially when you accept them for what they are, then they're not really worth it in my book.
Conversely, I have made some excellent friendships with other wonderful atheists and Skeptics that I would never have made if I wasn't an out atheist and as vocal as I am. The family, largely accept my atheism as part of my personality, some love to get into debates, so being out and vocal just adds an extra level of enjoyment for all concerned. Some of my family are likeminded, but most just can't seem to grasp the most basic rudiments of logical or rational discourse and tend to make the usual logical fallacies and cognitive biases. My journey of self discovery and what I think about coming out.
I am in the Navy, and I work as a military police investigator. When I made it clear in my office that I did not want to recieve their religious emails because I was atheist and had not time for it, I was instantly ostrisized. Since my line of work requires you to have a high moral standard, the attack on my character focused directly on my ethics and morals. Because the more religious people in my office think that "atheists" are the same as "Satanist", I have had an uphill battle trying to get the same fair treatment as my religious counterparts. I have had sprited debates with christians in the past, but this is the first time in my life that I have been discriminated against.