There seems to be an increasing number of pilots who think they "own" 121.5. Many of them seem to be commercial pilots who are ignorant of the purpose of the frequency. Maybe they think it's reserved for them to jump in to contact other company pilots who have either wrongly copied their next frequency, failed to dial it correctly, or have the incorrect "listen" switch selected..
"Shanwick, Shanwick...." is a commonly heard one.
The most blatant misuse I heard was a pilot with a German accent repeatedly using 121.5 to ask if anyone knew the result of the qualifying match of his national football team.