If the guy was innocent, he SHOULD have said "I'm taking pictures for a real estate company." Instead he got beligerent and ran off.
There is phenonenon going on where ordinary arab Americans are recruited by al-qaeda to do "TOURIST DRY-RUNS."
They take pictures of vulnerable sites, ask directions to nuclear sites or dams, leave luggage at vulnerable sites, act more than extremely suspicious on airline flights etc. If they are asked questions or are taken in for questioning by the FBI, they have a viable alibi.
If no questions are asked, they pass their information on.
But they are really just testing our defences, doing dry-runs and gathering intelligence.
We need to stop this activity which is usually run out of your local "Islam is a religion of Peace" mosque.
Any real estate professional that doesn't immediately offer you a business card when you inquire about his/her legitimate business is suspicious.
I know... I'm a Realtor.