Today most banks and online accounts use your cell phone as a point of verification. So publicizing it (by having it on your business card or email signature line) can create a new potential risk. The solution may be to get a free second phone number. There are paid and free mobile voice-over-internet-protocol (VOIP) services that allow you to do just that. A few to consider are Google Voice, Viber, Gushed, and Line2. You can then use this phone number for the wide audience, and give your actual cell phone number to family and close friends. This is a simple step to make yourself less of a target for fraud.