OK, here are just a few:
The students attempted to form friendships with federal employees, photograph their offices, tap their phone lines and infiltrate their databases.
Think about it. How many targets are likely to give some "art student" that kind of access? How stupid of a cover is that? It makes more sense for a spy to gain access as an after-hours janitor, or a cable TV installer.
According to some speculations, the Israelis' intelligence work enabled the spy ring to know in advance of the planned terror attack on September 11, without lifting a finger to prevent it.
How much art did they sell at flight schools? None of this regurgitated bovine matter says anything about art students hanging out at flight schools.