It's pretty difficult to find software engineers who take the patent system seriously. There are a few, but it's still pretty difficult. For the most part, they recognize that code is just a tool: you can make it do all sorts of things, given enough time and resources, but that doesn't mean that doing any particular thing in code is an "invention" that no one else should be able to do. And then, sometimes, they discover that something pretty basic and old has suddenly been given a patent. Brad Feld discusses his discovery that doubly linked lists were apparently patented
in 2006 (patent number 7,028,023
The prior art was extremely thin, only went back to 1995, and didn't mention that entire computer languages have been created around the list as a core data structure. One of my first Pascal programming exercises in high school (in 1981 -- on an Apple II using USDC Pascal) was to write a series of operations on lists, including both linked and doubly-linked lists (I always thought it was funny they were called "doubly-linked" instead of "double-linked" lists.) Anyone who ever graduated from MIT and took 6.001 learned to love all varieties of the linked list, including the doubly-linked one. That was 1984 for me by the way.
Ironically, Wikipedia had great entries -- with source code no less -- about both linked lists and doubly-linked lists. The linked list history goes back to 2001, well before the patent was filed.
Another day, another reason to question why software is patentable at all -- and to question who approves these kinds of patents.