"A man who represents himself before a court has a fool for a client".

presumably first said by a barrister.

Cunningham is a patent troll. The idea was inevitable. He didn't deserve a patent.

that the first system i saw what did the same as his patent (except the doorbell thing) was based on an ericsson t20 (using standard gsm 9600 baud dialup access) and was made years before the patent in question was filed. Afaik this is called prior art. (but the doorbell is good, so if the motion detector doesn't work or the visitor is invisible the system could still be triggered by the bell)

Surely a doorbell is in a sense a motion detector, just a very particular type of motion in a particular place - an in-out motion of 1-3mm within the area of the button.

Therefore, the doorbell feature can be ignored as it is covered by the motion detector and therefore the prior art nulls his patent.