The senseless carnage at Virginia Tech changed the landscape.
From Delaware County to Minnesota, seismic shifts in the way threats are perceived have forced up mountains on campuses where once there were molehills.
"I think everybody is taking these things much more seriously now," said S. Daniel Parker, senior vice president of Security on Campus Inc., a nonprofit college-crime prevention group. "Before, there was that mindframe that 'It doesn't happen here. It doesn't happen at colleges.' That has changed forever."
Delaware County Community College received messages from an e-mailer threatening to "kill everyone at this damn school," just 10 days after the April 16 massacre at Virginia Tech.
The college canceled four days of classes. When it reopened yesterday, students were no longer allowed to carry backpacks or purses.
Those ignoring the ban were allowed on school grounds only after security officers checked their bags, said Kathy Breslin, college vice president for institutional development.
"By and large, we were really surprisingly pleased at how well it went today," she said.
Students at the college's main campus in Marple Township said they felt safe amid the new precautions, including the backpack ban.
"I definitely think they did the right thing," senior Jaime Eleftherakis said. "But I feel like if someone was going to do something they wouldn't warn you first. I think it's either a cry for help or a copycat just trying to get on the news."
Senior James Magliano was comforted by the sight of state troopers patrolling the campus, but he doesn't pretend to believe they can stop a random act of violence.
"Just because they opened it today doesn't mean it's not going to happen today," he said, referring to the e-mailer's threat to strike on Monday or Tuesday.
Breslin said the backpack ban - and the police and security officers scattered throughout the five campuses in Chester and Delaware counties - will remain until the end of the semester.
After commencement on May 17, school officials will decide whether to continue the heightened security measures in the summer and fall, she said.
Brett Sokolow, president of the National Center for Higher Education Risk Management, said colleges will now respond more seriously to threats than before the Virgina Tech massacre, but he stressed the importance of finding a medium between the correct response and overreaction.
"If we're not careful we wind up turning college campuses into prison-like lockdowns," he said.
"Part of what makes college campuses the wonderful communities they are is the free and open access."
Said Marple Township Police Chief Tom Murray: "Could you make colleges and high school campuses secure? Sure, build a brick wall around them with one point of access and armed guards, and everybody goes through a metal detector. That's never going to happen."
Steven Healy, president of the International Association of Campus Law Enforcement Administrators and director of public safety at Princeton University, said each institution has to make the best decisions with the information available.
"Some of those decisions will be frowned upon, some will be applauded," he said.
"They have to respond to these situations in the best way they know how."
Healy, who testified before the U.S. Senate last week on the security of the nation's college campuses, said he sees April 16 as a "defining moment" in higher education
He said the events at Virginia Tech now loom heavily over every security decision made on college campuses.
"So you closed school for four days but you believe you've stopped a potentially dangerous situation," Healy said.
"So what is four days for a life, or many lives?"
Widener University spokesman Dan Hanson said it's impossible to say whether Widener's 100-acre campus would shut down in the event of a serious e-mail threat.
"There's no one way to handle things," he said. "It's situational, and the best thing you can do with a crisis-management plan is make it flexible to account for those types of scenarios."
Maurice Eldridge, vice president at Swarthmore College, couldn't say whether Swarthmore would react the same as Delaware County Community did if a similar threat was received.
For one, it's a residential college with about 1,400 people living on campus, not a commuter college like Delaware County's.
"You could be sure that we would respond, but there's not a stock response," he said.
"That's one of the difficulties in addressing an issue like this, because you cannot plan for every eventuality.