The second you write something original, you have copyright. If you are the first to publish it online, you have copyright. If someone steals it then publishes it online and then you publish it later, THEY have copyright. This is why it is dangerous to move online articles from one site to another...if someone steals your work and publishes it (or if they already have it online from having stolen it) while you're waiting for google to take it off their index, you won't be able to put it online. Some people go a step further and use the copyright symbol, etc...I'm not sure if this protects you from people who have stolen your work and published it or not. Your safest bet is publish it online where you want it to be and leave it there.