Under account settings it should say "verify account" with a list of things you can do like link this to your twitter account or verify your phone number and/or bank account. You don't need all of them (I don't have a bank account and I'm verified). You already have your FB verified so maybe just do the phone number one and I think it will be enough. It doesn't post your phone number on here, Listia just calls you with a code you have to enter and that's it. It's up to you but it does help.