Twitter has a new logo! The old one was a stylised blue bird, whereas the new one is a stylised blue bird.

Although the new one is made entirely out of overlapping circles, which is kind of cool.

What's not so cool is how the company seems to have gone brand identity mad now that they've got a slightly darker blue logo. Their new logos page lays out the "Twitter Trademark and Content Display Policy", which says what you can and can't do:

Do:

• Use our official, unmodified Twitter bird to represent our brand.
• Make sure the bird faces right.
• Allow for at least 150% buffer space around the bird. 

Don't:

• Use speech bubbles or words around the bird.
• Rotate or change the direction of the bird.
• Animate the bird.
• Duplicate the bird.
• Change the color of the bird.
• Use any other marks or logos to represent our brand.

Because they are still a nimble start-up at heart, they've even made a delightful infographic to illustrate all the ways in which they are sucking the fun out of their company:

Also:

Please remember to capitalize the T in Twitter and Tweet.

Oh, and:

[If you're advertising], make sure that if mentioning "Tweet," you include a direct reference to Twitter (for instance, "Tweet with Twitter") or display the Twitter brand or trademarks with the mention of "Tweet."

Because you wouldn't want the natural evolution of the English language to devalue your trademarks! That would be terrible.