In 2000, the courts in Victoria issued about 264 warrants for phone taps, roughly half of which were related to burglaries or rape. The source of this info was an article in The Age about July of this year (I wish they had searchable archives!). It's a fair bet to assume that the other approx 132 interceptions were drug related. Now, do you honestly think you're in the top 132 drug dealers in this state and as such, have somehow attracted the attention of the constabulary? No. Do you know anyone who's primary method of getting caught was via SMS or phone taps? No. And I mean "KNOW", not HEARD OF. Because we've all "heard" plenty of things about phone taps and SMS interception, most of it bollocks. Besides, with practically anonymous use of the public GSM network easily within reach of anyone smart enough to use prepaid, it's hardly a service worth tapping now is it!
There's so many fcuk*ing MYTHS surrounding phone taps. It's a labour intensive, slow and intrusive process, infinging lots of personal rights (yes, criminals do have them till they're proven to be a crim). In short - phone taps are very hard to justify, and courts demand more than a hunch to issue a warrant to tap phones. If your phone is tapped, it's to seal your fate in court (not land you there in the first place). It's my guess that the primary method by which drug-related criminals are identified and further investigation is justified would be via tip-offs, observations, the usual busts in clubs or doing actual deals. By the time your phone is tapped, that's the END of the cycle of investigation by police, not the beginning - you're going down and going down HARD. Nuff said.