In Netherlands, mobile phone operator Vodafone, for example, has introduced an SMS Spam filter, which will temporarily deny access to unidentified providers of SMS services.

This prevents Vodafone customers from being flooded by advertising messages by new and often unknown parties. Such messages usually mislead phone users into calling premium numbers whose call charges would be unknowingly billed to the phone users.

To get themselves off the block list, SMS providers have to agree to comply with the code of conduct Vodafone has for third parties that utilises its mobile network.

Vodafone's U.K arm has taken a slightly different approach to curb the growing number of spam and scam sprees.

Since premium rate SMS services, such as games and ringtone downloads have taken off with its customers, many unscrupulous premium service providers have decided to jump on the bandwagon and take advantage of customer confidence. These service providers will send volume SMSes to mobile phone users inviting them to respond to an advertised product or service using a premium rate number, sometimes baiting them with fake or misleading deals.

Vodafone customers who find themselves bombarded with such SMSes can report the abuse by forwarding it for free to Vodafone by typing VSPAM on their mobile keypad. Upon receiving the complaints, Vodafone will compile the reports and forward them to the Independent Committee for the Supervision of Standards of Telephone Information Services (ICSTIS) on a daily basis. ICTIS has in the past prosecuted several service providers for such offences and it will continue to take regulatory action against parties running such unscrupulous services.

Vodafone is operating in line with a self-regulating code of practice to stop companies sending unsolicited messages, which is also supported by other mobile phone operators in UK such as Orange and BTCellnet.

The code, drawn up by a new body, the Wireless Marketing Association, bans spamming and states all wireless marketing must be permission-based. It also establishes that mobile phone users who don't want to receive messages or promotions have a choice to opt out rather than opt in.

If successfully enforced and implemented, the code can help crack down on wireless advertisers who abuse customer confidence in mobile marketing.

In some countries, codes of conduct for mobile marketers are clearer and stricter for the purpose of preventing spam rather than curbing it. Belgium's Mobistar and Proximus's codes of conduct include rules on the size and legibility of text used by service providers to communicate the amounts charged for services proposed in their advertisements.

The codes also state that all games must be legal and comply in all respects with Belgian legislation, and the rates should always be reasonable and justifiable.

Such codes do not only apply to text messages or SMS but also to Multimedia Messaging Services or MMS.

On the more creative side, China has decided to deter phone spammers by giving them a taste of their own bitter, annoying medicine. In Hangzhou, the capital of Zhejiang province, businessmen who put up illegal advertisements which contain mobile numbers have become the target of a computerized phone-spammer.

The system rings the mobile phone numbers of illegal advertisers at 20-second intervals, bombarding them with pre-recorded voice messages, according to its official newspaper, the People's Daily.

Upon answering the call, the offenders hear the pre-recorded message: "You have broken the law by posting illegal ads. You must immediately stop this activity and go to the Hangzhou Urban Administrative Bureau for punishment."

If the wrongdoers choose to escape punishment by changing phone numbers, they would be faced with new set-up fees and inconvenience of switching numbers and also lose whatever business their ads might have generated.
The mobile barrage also prevents the likeliness of ad respondents getting through.

As for ordinary folks - they need not worry about getting spammed by accident as the phone numbers are taken from images of the illegal ads themselves. A senior official of the Hangzhou Urban Administrative Bureau also manually checks and approves the validity of the offending numbers before the bombardments can begin.

The use of text messaging to promote advertisements evidently has consumer benefits when carried out in a legal and responsible manner, but many mobile phone users are increasingly discouraged because of spam that the effectiveness of SMS advertising might be eventually compromised. Mobile phone operators and mobile marketers can help customers restore their confidence in using such services by making an active effort in preventing or at least cutting back on the amount of junk SMSes customers receive.