For an aging generation, "to drop a dime" means to tip off police, the expression coming from pay phones that were cheap and reliable.
Reliable still; often cheap, no longer a dime; but too often a rip-off.With phone deregulation, hundreds of providers got into the business of pay phones and hotel phones. With no convenient way of determining the cost of a long distance call, some providers felt free to soak the caller, who wouldn't discover the mini-fleecing until the phone bill arrived.
Enough irate callers complained that the Federal Communications Commission this week adopted some long overdue rules. After dialing a long distance number on a pay or hotel phone, the customer then has the option, by hitting a star or pound key, of learning how much the call will cost. If it's too much, hang up, no charge.
The FCC rule won't prevent callers from being ripped off, but at least they can't say they weren't warned. And that old expression "to drop a dime?" It's now "to leave a voice mail."