I will begin with giving an account of my experiences amongst the publicans.
Well, I must say that the first man who threw peas at me was a publican, while I was giving an entertainment to a few of my admirers in a public-house in a certain little village not far from Dundee; but, my dear friends, I wish it to be understood that the publican who threw the peas at me was not the landlord of the public-house , he was one of the party who came to hear me give my entertainment. Well, my dear readers, it was while I was singing my own song, “The Rattling Boy from Dundee Town” that he threw the peas at me…..the Rattling Boy told Barney Magee to give his glass of strong drink to the devil, meaning, I suppose, it was only fit for devils to make use of, not for God’s creatures. Because, my friends, too often has strong drink been the cause of seducing a beautiful young woman from her own true lover, and from her parents also…Therefore, my dear friends, the reason, I think, for the publican throwing the peas at me is because …he no doubt considered it had a teetotal tendency about it, and for that reason he had felt angry and had thrown the peas at me.
Reminiscences, in Poetic Gems selected from the works of William McGonagall, first published 1890.
Gert is pleased to say she has taken part in many a poetry reading and so far, not one person has thrown peas at her.
If you haven’t read McGonagall, you’re in for a rare treat.
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Gert Loveday's Fun with Books 
It used to be rotten tomatoes in my day.
Has that happened to you, Guy?
Loose lips and all that.
Sounds as if you too have a book in you.
Those peas would hurt, wouldn’t they? Rather nasty way to show your disapproval.
Leslie
From his tone here, it sounds as if this happened to McGonagall fairly often. But he remains philosophical.
You’d have to be philosopical about it if it happened that often.
Leslie