The first (number 7,130,389) covers a "digital notification and response system;" the second (7,496,183) covers a "method for providing digital notification" and the third (7,519,165) for a "method for providing digital notification and receiving responses."

The essence of TechRadium's complaint is that many of the features of it's Immediate Response Information System (IRIS) product can be done for free by users of Twitter.  This seems reminiscent of the Google complaint discussed previously (How free is free? Speech vs. beer at the Googleplex).

At first glance, this case may have merit, although a close reading of the legal filing shows that TechRadium chooses to highlight features of their product (such as distribution of messages to a subset of known recipients – they mention "parents of all ninth graders") that are simply impossible to achieve with Twitter – such message subsectioning can only be handled on the recipient-side, not the sender-side.

We await Twitter's response.