Googling random things can be fun, but there are definitely some words you should steer clear of.

One couple learned this the hard way when their innocent searches ended with police knocking on their door.

And it's not what you're thinking - nothing sexual, no aliens, and no attempts to hack government conspiracies.

Back in 2013, in Long Island, New York, Michele Catalano and her husband were looking up some simple household items online.

In her blog, she described: "Googling of certain things was creating a perfect storm of terrorism profiling."

The freelance writer thought she might get herself a pressure cooker whilst her husband wanted a new backpack.

Both did what you do these days: go online and search for 'pressure cookers' as well as 'backpacks.'

Catalano's husband did so from his work computer two days later, before leaving his job.

Seemingly harmless though, right?

Except for the unfortunate coincidence that the alleged Boston bombers were said to have hidden pressure cookers in backpacks.

Given the terror New York experienced just a decade prior, it raised some red flags with his employer.

IT staff flagged the searches, and his former employer reported it to the Suffolk County Police Department.

Not long after, several black SUVs pulled up at the couple's house in a bid to find evidence of terrorism.

So, if you don't want police to show up at your door, don't search the four words - 'pressure cooker bomb' alongside the word 'backpack'.

Michele described the surreal experience on her blog saying that her husband “saw three black SUVs in front of our house; two at the curb in front and one pulled up behind my husband’s Jeep in the driveway, as if to block him from leaving.”

The police have been so instant as they presumed the couple was googling the ingredients to make a bomb given their recent Google searches.

But all they found were some anxious homeowners.

The Suffolk County police released a statement following the raid: "Suffolk County Criminal Intelligence detectives received a tip from a Bay Shore-based computer company regarding suspicious computer searches conducted by a recently released employee."

Of course, the whole experience has left the couple a little shaken up.

Michele wrote on her blog: "Mostly I felt a great sense of anxiety. This is where we are at. Where you have no expectation of privacy. Where trying to learn how to cook some lentils could possibly land you on a watch list."

She humorously concluded: “All I know is if I’m going to buy a pressure cooker in the near future, I’m not doing it online.

“I’m scared. And not of the right things.”