The airplane's wings broke off before making that hole, obviously. Anyway, here's a page that explains a lot of why that video is nonsense:

Loose Change 2nd Edition Viewer Guide

If we tighten border security too much, that hinders international trade. Al-Queida's main goal when attacking the World TRADE Center was screwing with international trade, not killing Americans. Anyway, it hardly seems right to further the goals of Al-Queida in order to protect the US from terrorism. Besides, most people that are proponents of border security have ulterior motives (ie, they don't like mexicans coming into the US) that have nothing to do with terrorism.