Considering there's at least 400GB of data generated per day, I don't think it'll be readily available for the public as a download.

Jeez, 400 GB of text per day? How the hell?

EDIT: That's 11.5k tweets/sec. How do you get eleven thousand people to tweet every second?

Most of that data is not the content of the tweet itself, but the metadata associated with it. When I last checked, we were storing about a kilobyte of data for every tweet.

Also, tweets are limited to 140 characters, not bytes - chinese tweets typically take about 200-250 bytes, for example.

Yeah, I figured 300 bytes per Tweet, to be generous, but didn't realize it would take 1 kb of metadata. Thanks for that detail.

I have access to the Twitter gardenhose (which is equal to slightly less than 10% of the full volume). These are the RX and TX statistics from the machine that I've been using to gather data for a few months now:

RX bytes:18053724505080 (16.4 TiB) TX bytes:2686623557042 (2.4 TiB)

It works out at around 70GB/day, so I'd actually think that the full firehose would use considerably more data than 400GB/day (likely closer to 800GB).

Have you ever heard about the 'Human Brain Project' ?

Well, they produce 100 GB of data _per second_

Welcome to the real big data world.

Woah, 100 GB per second???!! What exactly do they do?

Edit: Never mind, this is what they are doing

"We would like to develop some kind of ‘google' brain where we can zoom in and out, see it from different perspectives and understand how brain structure and function is related."

Depends how much metadata there is with every tweet.

I took a random tweet on my timeline, and the JSON representation, with added metadata, weighs 8740 bytes.

With this figure, you would "only" need 500 tweets/sec to get 400GB a day.

There's a lot of people on Twitter, and a lot of bots, so that doesn't seem unreasonable to me.

Pick a topic you are familiar with. Open up a twitter search for it. Wait a while. See the inevitable storm of tweet-spam that sort of looks like social sharing.

Thousands of fake accounts are tweeting out nonsense all the time. Another example, there are multiple accounts that tweet items from HN (and presumably lots of other rss feeds).

Maybe it includes images.

it does not include images. A tweet object does include a bunch of metadata though: https://dev.twitter.com/docs/platform-objects/tweets

hell lot of data! First they have to find some alternative to zip these much of data!

Doesn't Twitter make a fair bit of money from selling access to various slices of their data? I'd be surprised if they released it all to the general public. I imagine scientists would have to be under some sort of NDA.

The Twitter terms of service prohibit sharing the data in the Tweets. Researchers are allowed to share tweet IDs and User IDs which can be used to identify a Tweet. Currently, Twitter collections are shared using this method -- I recently released a dataset of 120 million Tweet IDs which cover a sample of a months worth of data, and numerous other researchers have used these IDs to crawl Twitter and obtain the same dataset as I used in my experiments.