Who are all A's in Pretty Little Liars?

All of the Messages in the books are:

Aria: Surprise! I wonder what your pig puppet will have to say about this...-A

Hey Em, Sob! I've been replaced! You found another friend to kiss!-A

Spencer, Cover is an easy one. When someone covets something, they desire and lust after it. Usually it's something they can't have. You've always had that problem, though, haven't you?-A

Hey Hanna, Since prison food makes you fat, you know what Sean's gonna say? Not it!-A

Aria, Maybe he fools around with students all of the time. A lot of teachers do. Just ask your dad!-A

Hanna, Even Daddy doesn't love you best!-A

Aria, That's some kind of extra credit! Love ya, A P.S. Wonder what your mom would think if she found out about your dad's little, uh, study buddy... and that you knew!

A A A A A A: I already told you: Kissing your sister's boyfriend is WRONG.

Thought you might want this back. Love, A

Hanna, remember the KATE toothbrush? Thought so!-A

I'm still here. And I know everything.-A

Spence, I don't blame you for not telling them our little secret about Toby. The truth can be dangerous-and you don't want them getting hurt, do you?-A

Em! Still enjoying the same kinds of "activities" with your best friends, I see. Even though most of us have totally changed, it's nice to know you're still the same! Gonna tell everyone about your new love? Or shall I?-A

Hannakins: Mopping the floors at Bill Beach won't help you get your life back. Not even you could clean up this mess. And besides, I know something about you that'll guarantee you'll be Rosewood Day's it girl-ever again.-A

Naughty, naughty Aria! You should know better than to go after a teacher, anyway. It's girls like you who break up perfectly happy families.-A

P.S. Wondering who I am? I'm closer than you think-A

A A A A A A A: Two choices: Make it go away or tell your mom. I'm giving you till the stroke of midnight Saturday night, Cinderella. Or else.

A A A A A A A: Not sure how? Here's a hint: Strawberry Ridge Yoga studio. 7:30 a.m. Tomorrow. Be there.

Four simple Words: Hanna. Marin. Blinded. Jenna. What would Daddy think about you if he knew that? I'm watching you, Hanna, and you'd better do what I say.-A

Want an easy A? I think you know where to find it.-A

P.S. You hurt me, so I'm going to hurt you. Or maybe I should hurt a certain new boyfriend instead? You guys better watch out-I'll show up when you least expect it.-A

Hi again, Hanna! I want you to read Naomi and Rylie the sentences below just as they are written. No cheating! And if you don't everyone will know the truth about you-know-what. That includes Daddy.-A

Since you followed my orders so nicely yesterday, consider this a gift. Go to Foxy, now. Sean's there with another girl.

Poor, confused, Emily, I bet you could use a big warm girl hug right now, huh? Don't get too comfortable. It's not over until I say it is!-A

That is the first 2 books.