Shortly after Iranian "students" made prisoners of our embassy personnel in Tehran, I began to receive letters from readers who thought American TV ought to stop showing pictures of so-called students and their friends in Iranian street mobs.

The point was made that most of the demonstrating and shouting and death-to-Carter slogans were aimed at the American TV audience. Readers said that if we'd stop showing those scenes, the Iranians would lose much of their incentive for staging them -- and perhaps even for continuing to hold the prisoners.

Well, perhaps so. Many a kook engages in outrageous conduct these days for the express purpose of creating a media event, and we in the media play into their hands by giving them the coverage they want. Our excuse is, "It happened. We're in the business of reporting what happens. So we must cover it."

I didn't publish any of these "let's-black-out-the-students" letters because I wasn't sure which is the right side of this issue. And after weeks of thought, I'm still not sure.

Basically, I am opposed to blacking out news. Yet common sense tells me there are some things that responsible newsmen should voluntarily refrain from publicizing. Don't ask me to give you a list of what should be published or broadcast and what should not. I can't do that. Each case would have to be decided on its own merits.

Anyhow, while I'm still wondering whether it would be wise to stop showing scenes of fanatical demonstrators who think Uncle Sam has a forked tail and lives in the nether world, the Iranians have made our decision for us. They're kicking out American newsmen, news services and broadcasters.

Now we'll see whether the blackout helps or hurts the hostages -- or does neither. SCULL VOTES 'AYE'

Mae and Irving Jurrow of Chevy Chase sent a strong letter to Del. David Scull urging him to support the "loose loads" bill that is now back before the Maryland legislature. They sent me a copy of their letter to Scull, so I phoned him to ask his reaction.

"Well," he said dryly, "having myself lost a headlight and a windshield recently to missiles hurled back by vehicles ahead of me, I don't think there is any question about where I stand on the 'loose loads' bill.

"For that matter, I think the entire Montgomery County delegation is unaminous in supporting legislation to require truckers to cover loose loads, so that gravel and similar cargo won't fly off and become a threat to life and property.

"It's the people from the remainder of the state who don't give the bill the support it should have. There's no question about it; the trucking lobby comes down very hard on this bill, and so far they've managed to block it. Maybe this year will be different."

What about the "shabby tactics" of Committee Chairman Torrey Brown, who last year put the bill to a vote while most of its proponents were out to lunch? Scull sighed. "Brown was regarded as one of the outstanding people in the legislature until that episode," he said. "He seemed to be an enlightened progressive. Now one of the Baltimore papers ranks him as one of the '10 worst' -- all because of his handling of the 'loose loads' bill."

Mr. Chairman, do you get the feeling you're being watched? A MINOR CASUALTY

"Among the incidental casualties of the Iranian situation," writes Lewis E. Hawkins of Bethesda, "is the word blackmail.

"It's application was once properly limited to extortion through a threat to expose something shameful in the victim's past. It has been increasingly used in recent days to describe entirely different forms of extortion."

A good point, Lew. All blackmail is extortion but not all extortion is blackmail. The once precise meaning of blackmail may indeed become a casualty of the students at Terrorhan U. However, if we get our embassy personnel home with no other casualties than that, I'll be very happy. THE BRIGHTER SIDE

Smiles, a little humor magazine distributed by the Lawshe Instrument Co., carries the comment: "Anyone who believes that today's young people have it easy has never tried to tear down a set of steel goalposts set in concrete."

Changing Times, the Kiplinger magazine, also offers two observations that are worth repeating, to wit:

"History teaches that a man who would rather be right than president usually gets his wish."

"Second mortgages are said to be increasingly popular, which is good news. The first ones certainly weren't much fun."