It's an avalanche of suburban crime that has frustrated the police and rattled residents.
Elizabeth Burke is one of the victims in Cheltenham.
"My mom died about five years ago, they took all of her jewelry and $2, quarters, fast stuff," Burke said.
Police say the thieves operate at lightning speed, frequently hitting homes with burglar alarms.
"We've had a lot of alarms where we respond where we're there in minutes and it's already over and they're gone," Sgt. John Stillwagon of the Lower Merion Township Police said.
Police in Lower Merion and Cheltenham have beefed up patrols in neighborhoods where the burglars have been active.
"I'm out there, I'm riding the neighborhoods, we're all riding the neighborhoods, everybody in the staff is riding the neighborhoods," Chief John Norris of the Cheltenham Township Police said.
So far, though, the burglars have been elusive, grabbing mostly small items like jewelry and stuffing it into pillowcases.
The police are urging neighbors to look out for each other.
If you see an unfamiliar vehicle or work van in a neighbor's driveway, call police. They'd rather check out a false alarm than miss the chance to catch a thief.
"We have plenty of people out there. We'll be there to check these things out," Stillwagon said.