Junk caller number withheld ?

It's a shame, the TPS and the Information Commissioner's office can't do anything about junk calls, because unscrupulous companies are exploiting a loop hole. When asked why they are calling my non-publicly listed number they just claim the number has been generated using random modification of an existing number as a base -- which gets them off the hook with the IC's and TPS office. The legislation really needs to prevent all junk calls by default, sure if people really opt-into it then its fine, but we shouldn't be subject to interruption by these unscrupulous companies without opting-in. Regulation by "voluntary" industry groups like TPS/DMA/MPS isn't working because they are funded and represent financially the same companies they are supposed to be regulating! Conflict of interest ?

Junk calls often have the number displayed as "Withheld" (not to be confused with "Unknown"). I've been looking for a way to reject Withheld calls outright (aka Anonymous Call Rejection [ACR]), with a recorded message explaining that anonymous calls aren't accepted etc. I've not found a way to do it at present though. BT have their "Choose to Refuse" service on land-lines, which lets people reject individual numbers, and individual Withheld numbers (BT obviously knows the real number!). Also BT customers can dial *227# to reject all Withheld numbers from a BT line, and #227# to receive Withheld number calls again.. (A lot of legacy company PABX systems don't set a valid number still, so these won't get through) more info.

Apparently it is possible on some mobile networks, this page lists the GSM Caller ID codes, (background), however *30# sadly doesn't work on o2! Anyone able to reject Withheld calls on a UK mobile? Post a comment if you have managed it. This Caller ID FAQ has some useful info, which makes it sounds like o2 isn't working within the Telecoms Data Protection Directive (97/66/EC)!

In practice this kind of feature doesn't need to be server bound though, it could be a local setting to redirect to a special voice mail message etc. I'd code it myself if we had an open mobile phone platform!

Update: Samsung D900 can reject calls from Withheld or Unknown callers. N95 comes with Advanced Call Manager, as does Sony's P910i letting the user create whitelists and blacklists.