The American Civil Liberties Union, Planned Parenthood, advocates for battered women and people with unlisted telephone numbers have joined forces to protest US WEST Communications' plans to begin a market trial of its Caller ID service.

Among other things, the groups contend the six-month test involving about 70,000 residential lines in three of Boise's five "wire centers" could endanger spouses and children who move to shelters to escape abuse."This is an important issue of privacy and we believe it needs to be debated before US WEST launches this invasion of privacy," Jack Van Valkenburgh, director of the ACLU's Idaho chapter, said Tuesday.

The trial will be the first in the nation involving a Caller ID system that includes a display on the receiving end with both the caller's name and number. But the service also will allow callers, at no extra charge, to block the display of both their name and number when the receiving end has the service.