Net security, although complex, offers substantial rewards to those able to install security protecting software and/or assess companies' computer systems and recommend ways of preventing unauthorised access.
A good way of generating clients is to collect stories of security break-ins and mailshot companies offering your services.
Do security reviews for local firms to generate testimonials, as these will be a brilliant advertisement.
This is one of the most lucrative Net-related opportunities, you can charge serious money for this work. Remember, fear can be a very effective sales aid.