Justin raised some important questions about the latest RP ad.

Regarding the 19 hijackers, while several of them applied for student visas, none of them originated from countries currently defined as a terrorist state by the State Department. The sole hijacker that applied for and actually used a student visa, Hani Hanjour, was from Saudi Arabia. All of the others used B1/B2 visas (tourism, business travel).

As the official GAO report states (pdf):

Of the 19 hijackers, 18 received a total of 21 visas for temporary visits for business and pleasure, and 1 received 2 student visas.

In short, the general concept proposed in the ad would not have prevented these hijackers from receiving visas; this, despite the fact that most of the visa applications raised numerous red flags.

Note: in the past academic year, nearly 600,000 foreign students attended classes at American colleges and universities. I am sure all of them feel comfortable knowing that they could become suspects in the near Tancredian future.

See also:
The International Student Visa Process in the Post-9/11 World
9/11 and Terrorist Travel, by the National Commission (pdf)
Customs agent: Red flags over 9/11 hijacker’s visa