I used to know some govvies who were FBI analysts. There are more foiled terrorism plots than get reported for sure. That is the word at least at the FBI as of maybe 15 years ago.

Equally likely is that your friends were trying to make themselves sound more important and made unverifiable statements and let your existing trust relationship do the lifting.

That kid in middle school didn't have a girlfriend in Canada, and the FBI (documented on multiple occasions to have fabricated and entrapped people into "terror plots") didn't quietly stop a ton of terrorist plots.