To be fair i’m not the first one to have done this; Asterisk (the telephone exchange software) was developed in the USA where the FCC can barely ensure the numerous private companies actually keep the telephones working and laws protect businesses before consumers. The software (which only requires a cheap line card from China) can turn a 10 year old computer into a telephone exchange that is more powerful than those used in most UK villages 20-30 years ago (which also unfortunately attracts all kinds of hackers if you are not careful).
There is a whole set of messages available for download in various languages for announcements you would usually hear on a telephone network as well as some specifically for the purpose of confusing telemarketers or unwanted callers.
Another common practice is to play a SIT tone followed by the announcement “I’m sorry, weasels/badgers (the word varies between languages) have eaten our telephone system”. [they do gnaw up telephone wires run at low level unless they are protected against this].
