How Exactly Does one Weed Out "Home Grown" Terrorists?

In John Farmer Jr.'s article How to Spot a Terrorist, Farmer appeals to those who are unsure of their constitutional rights being adhered to and shows the contraversies of profiling Americans from both a constitutional and law enforcement standpoint. In the article, the author shows his support for a project that the Justice Department is undertaking called the National Suspicious Activity Reporting Initiative. This program allows people to report suspicious activity and stores it to look for patterns and potential danger. Many are worried that this initiative will put their constitutional rights in jeopardy, especially those relating to profiling based on race or appearance. The author says that it is a "balanced" way of obtaining information, as it holds suspicious activity as the primary cause of organization and not racial profiling. However, there is another controversy that is brought up; is enforcing this initiative taking away from the police's duty of law enforcement and placing it in intelligence? Farmer doesn't think so. He states that law enforcement officers are trained to look for suspicious activity anyways, such as someone robbing a house or a bank, and that this is no different.
Personally, I do not agree with the Farmer's claim that this will work. The whole initiative itself seems to have a lapse in logic from the start because it relies on the initiative of Joe Dirt to take time out of his workday and come in to report something that most likely isn't even an act of Terrorism. Then, the suspicious events have to be sifted through to find the relevant claims and correlated in a fashion that can't discriminate based on race or appearance. It may just be me, but it seems like it would be pretty difficult to find a terrorist if you don't know what he looks like. Additionally, if law enforcement officers are already trained to look for suspicious activity, then I don't see what additional relevant information this could bring them. His evidence he provides is good, but it seems like he is taking the evidence from sources that are likely to agree with him in the first place, such as a former FBI special agent. Ultimately, the threat of terrorism in our homeland is definitely a growing issue, but I don't think this is the appropriate way to act on it.