In 1886, the Social Democratic Federation, an avowedly Marxist party, held a demonstration in London that turned into a riot. In the aftermath, Engels made his opinion of this episode clear in several pieces of correspondence.

Of course you know what a meeting at 3pm in Trafalgar Square consists of: masses of the poor devils of the East End who vegetate in the borderland between working class and Lumpenproletariat, and a sufficient admixture of roughs and 'Arrys to leaven the whole into a mass ready for any "lark" up to a wild riot à propos de rien [about nothing]. Well, just at the time when this element was getting the upper hand (Kautsky who was there says das eigentliche Meeting war vorbei, die Keilerei ging los und so ging ich weg [the meeting proper was over, the brawling broke out and so I made off]), the wiseacres above named took these roughs in procession through Pall Mall and Piccadilly to Hyde Park for another and a truly revolutionary meeting. But on the road the roughs took matters into their own hands, smashed club windows and shop fronts, plundered first wine stores and bakers' shops, and then some jewellers' shops also, so that in Hyde Park our revolutionary swells had to preach "le calme et la modération"! While they were soft-sawdering, the wrecking and plundering went on outside in Audley St and even as far as Oxford St where at last the police intervened.

The absence of the police shows that the row was wanted, but that Hyndman and Co donnaient dans le piège [fell into the trap] is impardonable and brands them finally as not only helpless fools but also as scamps. They wanted to wash off the disgrace of their electoral manoeuvre, and now they have done an irreparable damage to the movement here.

To make a revolution – and that à propos de rien, when and where they liked – they thought nothing else was required but the paltry tricks sufficient to "boss" an agitation for any vile fad, packed meetings, lying in the press, and then, with five and twenty men secured to back them up, appealing to the masses to "rise" somehow, as best they might, against nobody in particular and everything in general, and trust to luck for the result.

During the procession, during this second little meeting and afterwards, the masses of the Lumpenproletariat, whom Hyndman had taken for the unemployed, streamed through some fashionable streets near by, looted jewellers' and other shops, used the loaves and legs of mutton which they had looted solely to break windows with, and dispersed without meeting any resistance. Only a remnant of them were broken up in Oxford Street by four, say four, policemen….

In addition a prosecution has been brought against Hyndman and Co which is so weak that the intention is that it should come to nothing…. The gentlemen certainly told a lot of tall stories about the social revolution, which, in front of that audience and in the absence of any organised support among the masses, was completely stupid; but I can hardly believe that the government is so foolish as to want to make martyrs of them.

These socialist gentlemen want to conjure up a movement by force and over night, something that here as elsewhere necessarily takes years of work; though it is also the case that, once it is under way and imposed on the masses through historic events, it may develop far more quickly here than on the Continent. But people like these cannot wait, and this leads to childish actions such as we are usually accustomed to seeing only from the anarchists.

Shouting about revolution, which in France passes off harmlessly as stale stuff, is utter nonsense here among the totally unprepared masses and has the effect of scaring away the proletariat, only exciting the demoralised elements. It absolutely cannot be understood here as anything but a summons to looting, which accordingly followed and has brought discredit which will last a long time here, among the workers too.

What has been achieved – among the bourgeois public – is the identification of socialism with looting, and even though that does not make the matter much worse, still it is certainly no gain to us.

http://www.whatnextjournal.org.uk/Pages/Back/Wnext19/Engels.html