IT COULD NOT have been much of a surprise last June when more than 300 anti-nuclear demonstrators showed up at the Black Fox power plant near Tulsa, Okla. The surprise came later.

The demonstration had been well-publicized as these things usually are, and the media were out in force, along with utility officials and security officers. When the demonstrators cross a fence barring public access to the construction site, almost everyone knew what would happen next. Three hundred and nineteen people were arrested for trespassing.

Then came the surprise. The nine reporters and television cameramen who had crossed the fence to cover the event were also arrested. That doesn't happen often, although these were not the first journalists arrested for doing their jobs. It happened this time because the nine had accompanied the demonstrators instead of doing what the utility wanted them to do. The company had provided a roped-in area for the press some distance away from the action. The reporters who went to the roped-in area -- and had difficulty seeing and hearing what was going on -- were not arrested, even though they, too, eventually appeared with an official escort at the scene of the crimes.

But the surprise didn't end then.After a jury refused to convict the demonstrators, Judge David Allen Box dismissed all 319 cases. But last Tuesday, when the cases of the nine journalists came before him, he found them guilty and fined them $25 each.

Pretty weird. If the journalists were guilty, so were the demonstrators. It takes some pretty odd logic for a judge to find nine people guilty after a local jury over which he presided has refused to find 319 other people guilty of the identical offense.

But there is more. The utility had set up that roped-in viewing area in an effort, among other things, to minimize news coverage of a demonstration it didn't care for. The message of the convictions to other companies is clear: set up a viewing area for the press -- reporters can watch through binoculars -- and you don't have to worry so much about the publicity of demonstrations at your plant. The fact that the event is newsworthy or that arrests are made is irrelevant as long as the arrests occur on private property.

Journalists covering newsworthy events sometimes do things for which they can be arrested legitimately -- the incitement of crowds or the obstruction of police work, for instance. But in this case the prosecution conceded the nine were doing nothing other than peacefully observing a "significant event." Some law -- some judge.