The FBI and other members of the state’s Joint Terrorism Task Force say there is no imminent danger based on ongoing intelligence assessments, though they are beefing up patrols at major transportation hubs. 

And so passengers used to long lines at Logan security found those lines even longer.   

As often happens in the aftermath of terrorist attacks, a common security refrain heard over loudspeakers took on added meaning: “If you see something say something.”   

Congressman Bill Keating told WGBH that the Brussels attacks makes a federal study he commissioned on airport security just that much more important.

“Someone could see what’s happening there and decide more or less to copycat the activity here,” said Keating.  
“We have to do a stronger risk assessment on the whole footprint of airports, from the parking lots to the curbs, all through the perimeter. Beyond just the gate where the electronic screening occurs.” 
That would invariably lead to even longer waits. But Keating says, there's always a balance between security and convenience.