Peter Kafka of MediaMemo estimates that the sale netted between $10 and $15 million. TechCrunch also speculates that the price tag was around $10 million. Justin Shaffer, the founder and CEO of Hot Potato, would not comment on the financial details of the acquisition.

In a statement to Mashable(), Facebook() spokesperson Jonny Thaw said, “We’re excited to confirm that we recently acquired Hot Potato, a service that helps people socialize around live events and share what they’re doing with friends. We’ve admired for some time how Hot Potato is tackling this space and look forward to working with them to bring Hot Potato innovations to Facebook.”

Thaw would not comment on the terms of the acquisition. Hot Potato’s eight employees, most of whom are developers, will be moving to Palo Alto shortly; Shaffer has already started at Facebook. Hot Potato raised a $1.42 million Series A round late last year and was backed by RRE Ventures, Betaworks and Ron Conway. It’s not clear how many use the application.

Although Facebook would not comment on what Hot Potato will be working on, it likely bought the company, which launched as a mobile-based application last November, to improve the functionality around status updates and its newly launched Facebook Places feature, and to tap into real-time updates around events. Hot Potato’s announcement hints that some of its features will be integrated into Facebook, as well: “Today, we’re thrilled to announce that some of the features and thinking behind Hot Potato are going to be exposed to a much larger audience: We’ve been acquired by Facebook.”

According to its blog(), Hot Potato will be wrapping up operations and delete all user data in about a month. The blog stressed that “no user data or account information will be kept by Facebook.”

The status message, which reads: “WOW! Justin Bieber Is Giving Away Free Concert Tickets Now!” is followed by a bit.ly link to a rogue Facebook application that, if installed, posts the same message on a user’s Facebook status, security software firm Sophos has learned.

It also creates a wall post claiming that said user, “just snagged 4 free tickets to see Justin Bieber! Justin Bieber World Tour” under the headline “Justin Bieber Free Concert Ticket Giveaway!”

Those who continue on with the application are then prompted to enter their mobile phone number and check an agreement to enter a contest to win £50,000. What entering the “contest” actually does is trick users into subscribing to a premium rate service that costs £4.50 per week, according to Sophos.

What makes this app especially dangerous is that it specifically targets Justin Bieber’s young — and significantly large — fanbase, who are likely less familiar with common scamming techniques than older users. This is in fact the second Bieber-related Facebook scam we’ve come across this week.

As always, be wary of apps that ask for permission to post to your Facebook wall and status updates, as well as solicitations for your personal information. If you’re a parent, it’s worthwhile to teach your kids how to detect these as well.

We don’t know whether it’s a bug or an intentional inside joke, but Facebook’s developers have done a few jokes and pranks in the past, so we wouldn’t put it past them. Of course, we’re also not sure why you’d want to block him; it’s not likely that he’s spamming your wall with unwanted FarmVille invitations.

Nevertheless, there’s a website called Block Zuck that acts as a sort of catharsis for people fed up with some of Facebook’s recent choices, such as allowing your friends to location-tag you in Facebook Places by default with no confirmation from you.

Maybe you’ll want to block Zuckerberg after you see the fictionalization of his early years at Facebook in the upcoming movie The Social Network just for the principle of the thing. Or maybe you’ll just laugh a little at this easter egg or bug and move on with your life.

Either way, you can verify this by going to Zuckerberg’s Facebook profile, scrolling down near the button of the left panel and clicking “Report/Block this person,” then checking “Block this person” and clicking “Submit.”

Assuming this isn’t just a bug, is it a funny easter egg, or a joke in bad taste? Let us know in the comments

The report indicates that access to this personal information was accessible via Facebook’s privacy settings, with the Preview My Profile feature creating the loophole to access the private live chats of friends.

With Preview My Profile, users can view how their profile appears to any given Facebook friend. The bug apparently let those users see the live chats and friend requests of the friend in question.

Unfortunately for the company, this is not the first time users’ personal information has been exposed without consent. Earlier this year, user e-mail addresses were exposed in a hiccup following a site update. The company is also facing scrutiny from users and politicians displeased with the opt-in settings of Facebook’s Open Graph implementation.

We’ve reached out to Facebook for more information and comment on the situation, but as of now there is no word on how widespread of an issue this is or was, or when Facebook Chat will be re-enabled.

We’ll be rolling this out slowly going forward, but fairly soon you’ll notice our new Chat bar at the bottom of your browser—no installation or assembly required. From this bar you can view your list of online friends and open conversations with any or all of them. There’s no need to setup a “buddy list.” Unlike the Wall or Inbox, the messages are delivered and displayed to your friend as soon as they’re sent, so you should expect a response right away and without any page loading. Of course, Chat has to play nice with the rest of the Facebook experience. You can collapse conversations to get them out of the way, and go offline if you don’t want to use Chat at all. Chat is there when you want it, and tucked away when you don’t.

We’re working on pulling other features of the site into the real- time Chat world. Your notifications will now arrive in the Chat bar, and while chatting you’ll see your friend’s Mini-Feed activity thrown into the conversation, as it occurs.

Before we jump head-first into this new real-time approach to Facebook, it’s worth spending some time thinking about privacy. Conversations are one-to-one, completely private, and only between Facebook friends. The message history is saved from page to page, and even between login sessions, but it is not logged permanently. Should you wish to clear out the history immediately, there’s a link provided in each conversation to do so. If you don’t want your Mini-Feed stories embedded into your conversations, you can turn off that feature from either the Mini-Feed privacy page or the Chat settings panel. As Chat grows and evolves, we’ll continue to make sure that you are in control.

Chat is by no means a new concept, as instant messaging systems have been around for over a decade. But just as other features on Facebook have allowed friends to communicate more efficiently than before, we hope Facebook Chat will make it easier to connect instantly.

If you want to read over something you’ve written, but that has not yet been deleted, just open the chat window you used to chat with the person you want to read about. You won’t be able to read older chats though, nor can you view the chat history between you and someone who’s not currently online. Hopefully these options will be coming soon.

There are more, test out some of your own.

You can easily toggle your message notification option on Facebook Chat. Just click on the chat menu and then click on the settings link in the pop up bar. Where you see the option that says “Play Sound for New Messages” you can either click it on or off.