Those of us in the US can't.
R' Weiner holds you can do
melacha b'tzina on the second day of Yom Tov, as long as there is absolutely 0 percent chance that anyone will notice. for example, you can't even turn the light in your room on and off, since people can see under the door.
I asked him if I am allowed to email another American-Israeli currently in America, and he told me I can't, because that is like it's "leaving the room". It would stand to reason that posting on DDF falls under the same heading.