We’re shocked that the Maine State Police have resorted to a controversial DNA dragnet to, apparently, help solve a vandalism case.

First, it is absurdly out of proportion to the severity of the crime.

Second, it is an invasion of privacy.

Third, it casts completely unwarranted aspersions on the characters of everyone involved in the environmental movement in Maine.

Finally, it is completely contrary to the basic presumption of innocence that underlies our criminal justice system.

It was revealed last week that the State Police have asked about a dozen environmental activists in Maine to provide samples of their DNA as part of a criminal investigation.

Most wisely refused, according to a Maine Public Radio report.

The request appears linked to an incident in April when the group Earth First! planned to camp on Sears Island in defiance of a ban on camping on the state-owned property.

The activists later decided to camp on nearby private land, but only after some interaction between police and activists on the causeway linking the island to the mainland.

There were no arrests and no citations were issued. But, a month later, police seeking DNA samples knocked on the doors of people they identified as having been at the Sears Island protest.

“It was totally voluntary,” state police spokesman Steve McCausland said last week. “A couple said yes.’ Most said no.'”

Yet we wonder how voluntary it seems when a uniformed officer shows up on your doorstep with a mouth swab in hand.

DNA dragnets have been popping up around the country, most recently in the Cape Cod town of Truro where police tried to voluntarily test the DNA of all male residents to help break a long-unsolved murder case.

A quick check of the Web shows that DNA dragnets have been used, with mixed results, in a variety of long-standing murder investigations.

It is unclear why the Maine State Police feel they need the DNA of environmentalists, but it appears likely to involve allegations far less serious than murder.

In November 2005, vandals hit homes owned by two officials of Plum Creek Timber Co., the company proposing a large development in the Moosehead Lake region.

The vandalism was quickly denounced by environmental groups, and we are unaware of any evidence linking the vandalism to any organized group.

If the DNA samples are being collected in connection with the Plum Creek vandalism, the use of this technique is wildly out of proportion to the seriousness of the crime.

A stubborn murder investigation is one thing, vandalism is another.

Moreover, DNA dragnets are unfair and a dangerous invasion of privacy. They put innocent people in the position of having to prove their innocence. In our society, it’s the state’s job to prove guilt.

The dragnets also pressure people into providing DNA samples with little assurance of how that information will be used in the future.

Many fear that insurance providers will one day gain access to DNA profiles, identify people with predispositions to certain illnesses and deny them coverage.

Or, they fear an employer could refuse to hire a person if they knew she was more likely to develop an illness. Or, that drug companies could obtain profiles and begin marketing to people based upon their likelihood of developing a certain illness.

We also fear State Police have set a dangerous precedent by making suspects out of citizens for their political activism. Police apparently do not have enough evidence or probable cause to seek a warrant to obtain DNA samples.

That’s dangerous.

Maine has been amazingly free of the kind of environmental violence and extremism that has been seen in other parts of the country.

We hope it stays that way. But the threat of DNA fishing expeditions threatens civic involvement and does nothing to make any of us feel safer.