Although Twitter famously has a pending patent on the familiar "pull-to-refresh" gesture, the company may have just acquired something more valuable: a patent on the Twitter messaging service itself. The new patent issued today with Twitter founders Jack Dorsey and Biz Stone listed as inventors, and broadly describes a messaging service in which users follow each other and sent messages don't have specific recipients, but are rather sent and displayed to those followers by the system itself. That's exactly how Twitter works, of course — it's definitely more of a broadcasting system than a direct messaging service, and the patent claims explicitly make reference to "broadcasting an update message" several times.

Jack Dorsey and Biz Stone, inventors

Twitter filed for the patent in 2007, but it's doubtful the company will pursue any litigation against competing services with it now that it's in hand — the company has very publicly promised to only use patents defensively, and last year introduced the Innovator's Patent Agreement to codify that promise and require permission from its employees before suing offensively. But competing companies like Facebook will have to evaluate their products carefully against Twitter's very broad claims on virtually any service that allows messages to be sent to a large group of unaddressed recipients who follow the sender.

Look Ma, I'm officially an inventor (my dream as a kid)! mobile.theverge.com/2013/3/19/4124… — Biz Stone (@biz) March 19, 2013

Twitter confirmed that the patent was issued earlier today, and provided the following statement: "Like many companies, we apply for patents on a bunch of our inventions. We also think a lot about how those patents may be used in the future, which is why we introduced the Innovator's Patent Agreement to keep control of those patents in the hands of engineers and designers." We'll see how the industry reacts to such a broad patent combined with such a unique and equally broad promise to avoid litigation.