Good advice that some web pundits hand out is that you should own your own profile, your own web identity.
That means you shouldn't depend on, e.g., Google, Facebook, or Twitter as your only presence and identity on-line. It's a good idea to register yourself with all of them, and *carefully* control what information is there, but it's also a good idea to have your own site which you own and fully control and which is always the main place people can go to find out what you want them to know.
To do this is cheap. The main requirement is a domain name, yourname.com or whatever you want to call it. Of course you'll be limited by what's available. You can get these from, e.g., hover.com, for about $15 a year. Once you register a domain name, you legally own it and can always control what information it points to.
From there you can build a home page, even a minimal one, with Google Sites, Wordpress.com, or even Facebook or Twitter. You can also buy a site web hosting service like Squarespace.com.
Then you just forward your domain there. If something happens to the site you're pointing to, then you just forward your domain name to another site.
The main idea is that this gives you a somewhat “permanent” address on the web. Your “permanent” address used to be your email address, but that turned out to be a bad idea as spam and other email abuses blossomed.
From this main identity page, you can point to any and all of any other sites you'd like to point people to such as a blog or even your Facebook page if you must.