I don't mind in principle if you play spammers dirty tricks - I am tired of them myself. However, I suggest you bear in mind two points: 1) Justified or not, they might still sue you for this sort of tricks. 2) Make sure the phone number really belongs to a spammer; you might easily be playing tricks on some legitimate business.

>Today I received the following delightful offer:
>
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>Get a Diplma!
>Answer a few key questions for us by calling the provided number.
>
>1-212-629-xxx, day or night.
>To stop us from bothering you call 1-801-757-xxx and leave the email address where you received this.
>
>Wheere mid iss tthe buufid of the reeceived messagee. The handdler fuunctioon ccan bbe used to uunpackk aandd prroccess tthe rreecceeivvedd message buffffer. PPVM auutommatticalllyy savves the cuurrentA MIFFFF iimaage ffile coonnsistt off two sectionss. TThe ffirstt secctioon iss a heeadeerr coomposed of keeys deescriibing tthe imagee inn textt form. The next secttiion is the binarry imaage daata. Thee header is separrated from the iimagge dataa by a :: chaaraaccter immmmediattelly followwed by a newliinne. The MIFF headeer is coomposed entireely of LATIIN-1 chaarraacters. TThe fields in the hheeader arre keyy andd vallue.
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>
>I was so pleased to receive this that I decided to help him out. I am involved in a VOIP trial here in New Zealand, zero cost at present and they want us to make lots of international calls. So, I have prepared my PC to call both provided numbers constantly, playing Bauhaus's "Bela Lugosi's Dead" to whoever is lucky enough to answer and not hanging up until they do. The first number has an answerphone that records 40 seconds of song each time. The chances of blocking or tracking are almost nil, since during the trial the call will be emitted semi-randomly by a provider in the US.