Most of the damaged churches had one thing in common: they were in out-of-the-way country places with minority Catholic populations and not far from strong loyalist towns like Lisburn, Portadown, Banbridge and Antrim.
Many of the places were marked by good relations between Catholics and Protestants.
The pattern tended to be similar.
The smell of smoke at around 1.30 a.m. alerted neighbours to the fire in the 214-year-old church at Magheragall, near Lisburn. By the time the fire brigade arrived the little chapel had been engulfed by flames.
By sunrise there was little left of the interior or the roof - altar, altar rails, pews, sacristy, floor were all a tangle of black, twisted debris.
"There's nothing left only the four walls - the heat must have been powerful," said a local Protestant farmer who had turned up to offer words of sympathy.
"It must have been outsiders. We know all the people who live around here personally. We get along and respect each other's differences and right to worship."
Ms Eilish Higgins, a local midwife whose husband was the church's temporary caretaker, said she was "heartbroken".
Hers is only one of two Catholic families on the adjoining road, and she is one of only two Catholic members of the local Women's Institute.
She was unable to get to work yesterday morning because of the number of calls from Protestant neighbours expressing outrage and offering solidarity.
An earlier attempt to burn the church and its unused school hall had been made in 1995, but the petrol-soaked rags left at both their doors had failed to ignite.
A few miles to the west, St James's Church at Aldergrove, near the airport, was another 200year-old church to suffer the arsonists' attentions.
Its roof is beyond repair and the sacristy and altar areas were destroyed.
A young woman returning home in the early hours of the morning saw the flames and phoned the fire brigade when she got back to her house in neighbouring Crumlin.
"It's a simple, country church, but there is tremendous affection for it," said Father John Burns, a recently ordained young priest who grew up in the parish.
He was standing with a group of dark-suited men waiting for the burial of a four-year-old local child who had died in a farm accident. The cemetery, where the Catholic student Ciaran Heffron, murdered in April - probably by the LVF - is also buried, lies across the road from the church.
This is another area - around 70 per cent Protestant, 30 per cent Catholic - where community relations are good. The church has never been touched before.
Everyone drinks in The Grove Bar beside the church. "Sectarianism is not brought into it at all here," said Ms Mary Kelly, the owner's daughter. "Our neighbours wouldn't call the people who did this Protestants, just evil-minded people."
Ms Ethel Bushe, a member of the Church of Ireland who works in the bar, agreed. She had helped to clean the chapel two weeks ago to get it ready for Mary's sister's wedding.
Down across the "county line" in Armagh, another little church at Mullavilly, four miles outside Portadown, had been undergoing major repairs after a serious arson attack 15 months ago. It was easy enough for the arsonists to set the open felt on the unslated roof alight.
A neighbour's son, a Protestant, sounded the alarm, and the fire brigade arrived in time to confine the damage to a small corner of the roof. The 227-year-old church, one of the oldest in the Armagh diocese, is situated on the edge of the largely Protestant village of Laurelvale, with its beautifully kept cricket pitch, smart modern bungalows and Union flag-bedecked main street.
To many Portadown Protestants, this is part of historic contested territory. The little Church of the Immaculate Conception, as well as its parochial hall and school, were attacked several times in the 1970s. The April 1997 attack left it without a roof and its interior totally destroyed. Its sister church, at nearby Stonebridge, was badly damaged in a similar assault two years ago.
"When you live with it you come to expect it. It's what's known as culture," said one elderly farmer with heavy irony.