kbrosnan, I traced it down. It was freshplayerplugin from a Webupd8 PPA, not Pipelight.
I have just written up an email explaining the crashing and sent it to the website owner, who also does the PPAs.
Basically I warned him to expect crashing if he tries it out.
That way, if he checks his mail, he will have a heads up and not need to investigate as much.