Don't worry - the patent has expired so you won't have to pay royalties when your kids build one, but the amazing thing is that this patent was ever granted to begin with!

As if there was any doubt in your mind that America's legal system is bloated, over-complicated and full of corruption, here is some more proof: someone actually applied-for and received a patent for building a tin-can and string telephone. The type kids have built and played with for decades. The telephone that pretty much anyone alive can tell you about.

Now, you don't have to worry about Johnny Lawyer knocking on your door because your kids built one of these fantastic inventions in their treehouse because the patent has expired. However, it should make you think about just how stupid the legal system has become that someone would even consider paying to file such a ludicrous patent.

It's my understanding, and IANAL (I Am Not A Lawyer) that a patent idea should be a non-obvious way to build, design, or create something. It should be novel, at least at the time of the filing (we have to allow for this because over time, things that appear to be "magic" today will be commonplace in 20 years). A patent describes the method, technique, or apparatus in such a way that someone reasonably skilled in the field or art should be able to understand the concept in sufficient detail to recreate something similar to the described idea.

In this case, on February 17, 1978, two Illinois "inventors" applied-for and received the patent for the string and tin-can telephone. Now, again, IANAL, but it seems to me that children have been building these "devices" for decades, so there is (or should be) plenty of prior-art which would precede this concept, thus causing the patent office to reject the idea. The idea, at least in 1978, was not novel or ingenious. The people reasonably skilled in the field of tin-can telephones are 8 year old children. Can you see the stupidity?

Maybe this patent filing is simply the result of the "inventors" having too much time and/or money and they wanted to see if they could get such a ludicrous patent issued. I'm sure that, if they actually tried to press for intellectual property infringement in court, the patent would be ruled invalid, but still...