Now y'all know that quote marks around a word or phrase often indicate supposed, alleged or so-called.
Peter's "mates" left him in the park to die.
I sacked the "experts" and did it myself.
(Note: don't use quote marks as well as the words supposed, alleged or so-called - that's tautologising. For example: don't say Peter's so-called "mates" left him in the park to die.)
This means using quote marks for emphasis can convey quite the opposite meaning to that which is intended. (All pics pilfered from the net.)
Reference "Grammar Rules: Writing with Military Precision" by Craig Shrives (2011)