This is a problem that should not be 'taken lightly'. [=this is a problem that should be treated seriously]
Considering the harm he did, he's 'gotten off lightly' with only a warning.
Our troops were armed too 'lightly' to take on the heavily armed invaders.
(..) Have Skyler bring the kids here. That is not going to happen. I don't even know who I'm talking to. Tread lightly. Hank, are you arresting me? Am I under arrest!? Okay boys, take it all, let's get everything. Do you know about (..)2013 TvShow: Breaking Bad Title: Confessions Season: 5 Episode 11