Shakespeare Did It Syndrome (or SDIS) is the unfortunate misconception that some people seem to have that William Shakespeare was and is a god.
This odd condition is manifested when a person decides to defend something on the merit of Shakespeare's name. This occurs in a few different forms:
1) Perhaps you've heard or seen people defending every single piece of work that Shakespeare ever wrote, claiming that he was a genius and that all of his works contain exemplary language and plot and characters and etc. This is simply not the case, and an unfair assumption to boot. We should allow that everyone, even a literary master, has some bad days. Said literary master might even happen to write on some of those days.
2) The second form of SDIS is more far-reaching; the person who defends a piece of literary work on the basis that it contains methods and styles used by Shakespeare. Don't laugh, this happens. This, unfortunately, is even more ridiculous than the first. This is breaking down the work of a genius into a group of ideas and styles that can be copied. Does this make the copier great? I think not...
In any case, the treatments for SDIS vary, depending on the person. Maybe just pointing out the fallacy of the argument will be enough. In some hard-core cases, a system of ignoring and smiting with hammers might well do the job. If it's a self-diagnosed case, then just try not to do it. It's an insult to English literature and to the great writer that Shakespeare really was. He just wasn't infallible.