The prime example: Craigslist forums.
Log into the Craigslist Atheist Forum and post about your faith, or, perish the thought, "evangelize", and in short order some Atheist will tell you to get out of that forum. Seems that the Atheist Forum is ONLY for Atheism and anybody who speaks positively of religion is a "troll" and should be banned from making posts. Posting about God in a positive sense just isn't "proper" in THEIR forum.
At any time in the Religious Forum, you'll find several Atheists making posts that insult and belittle Christians, Christianity, Mormonism, or the JW faith. Seems it's A-O-K for Atheists to enter a religious forum and promote Atheism (through the insulting of religion). They call it "religious discussion" (although last time I checked, I didn't see much 'discussion' among all the childish taunts, F-bombs, and pictures of Jesus riding a dinosaur).
You see, the Atheists will remind you that the Religious Forum isn't strictly a "Christian" form (of course, it isn't an Atheism Forum... they already have one that they jealously protect). The Atheists will also remind you have a "right" to go to any forum they choose (if YOU, however, attempt to support Christianity in "their" forum, you will be harassed until you leave or they will have you banned by the Admin Staff).
See how it works?
Aren't Atheists and their sense of moral relativism just wonderful?