In his leadership of the Russian revolutionary movement, Lenin had numerous experiences with agents provocateurs of the Tsarist government. Here are a few of them (italics and boldface added).
Excerpt from Lenin, What Is To Be Done, 1901
Internet source: http://www.marxists.org/archive/lenin/works/1901/witbd/ch04.htm#04_A
... as soon as serious war operations began (and they began in fact with the strikes in the summer of 1896), the defects in our fighting organisations made themselves felt to an ever-increasing degree. The government, at first thrown into confusion and committing a number of blunders (e.g., its appeal to the public describing the misdeeds of the socialists, or the banishment of workers from the capitals to provincial industrial centres), very soon adapted itself to the new conditions of the struggle and managed to deploy well its perfectly equipped detachments of agents provocateurs, spies, and gendarmes. Raids became so frequent, affected such a vast number of people, and cleared out the local study circles so thoroughly that the masses of the workers lost literally all their leaders, the movement assumed an amazingly sporadic character, and it became utterly impossible to establish continuity and coherence in the work. The terrible dispersion of the local leaders; the fortuitous character of the study circle memberships; the lack of training in, and the narrow outlook on, theoretical, political, and organisational questions were all the inevitable result of the conditions described above. Things have reached such a pass that in several places the workers, because of our lack of self-restraint and the inability to maintain secrecy, begin to lose faith in the intellectuals and to avoid them; the intellectuals, they say, are much too careless and cause police raids!
Footnote one from Lenin, The Reorganisation of the Party,1905
Internet source: http://www.marxists.org/archive/lenin/works/1905/reorg/i.htm
{1} The “Independents"—members of the Independent Social Labour Party, an organisation of agents-provocateurs founded in St. Petersburg in the autumn of 1905 on instructions from the tsarist government, with the direct assistance of the secret police. The party, which was Zubatovist in type, sought to divert the workers from the revolutionary struggle. Its programme, published in the magazine Russky Rabochy (The Russian Worker), No. 4, on December 15 (28), 1905, called for combating Social-Democracy. By the beginning of 1908 the party had ceased to exist, having failed among the masses of the workers.
Footnote five from Lenin, Some Features of the Present Collapse, 1908
Internet source: http://www.marxists.org/archive/lenin/works/1908/jul/02.htm
{5} This refers to the uprisings in Sveaborg (see present edition, Note 42) and Kronstadt. The uprising of sailors and soldiers in Kronstadt started on July 19 (August 1), 1906, after news had been received of the uprising in Sveaborg. In the spring and summer of 1906, under the leadership of the Bolsheviks, preparations had gone forward for an armed uprising of workers, soldiers and sailors in Kronstadt. These preparations, however, were considerably complicated by the arrest on July 9 (22) of most of the members of the military and workers' organisation of the R. S. D. L. P. Nevertheless, with the support of the St. Petersburg Committee and its representative, D. Z. Manuilsky, the Bolsheviks went forward with their preparations for an armed uprising, while at the same time rebuffing the Socialist-Revolutionaries, who had been provoking a premature uprising. When the spontaneous Sveaborg rising broke out the preparations for an armed uprising in Kronstadt had not been completed, but in view of the events in Sveaborg the uprising in Kronstadt had to be begun prematurely. The Bolsheviks took the lead in order to make the action as organised as possible. At a pre-arranged signal the struggle was started almost simultaneously by minemen, sappers, soldiers of the electric-mine company, and sailors of the First and Second Naval Divisions, who were joined by some of the armed workers. The government, however, had received information from agents provocateurs of the time fixed for the uprising, and had prepared in advance for the fight. Another factor that worked against the uprising was the disruptive activities of the Socialist-Revolutionaries. By the morning of July 20 (August 2) the uprising was suppressed.
Footnote one from Lenin, What Next? On the Tasks Confronting the Workers’ Parties with Regard to Opportunism and Social-Chauvinism, 1915
Internet source: http://www.marxists.org/archive/lenin/works/1915/jan/09.htm
[1] The Bolshevik deputies to the Fourth Duma were arrested on the night of November 5-6 (18-19),1914. The pretext for their arrest was their participation in a conference they convened in the village of Ozerki, near Petrograd.
Held on November 2-4 (15-17), the conference was attended by representatives of the Bolshevik organisations of Petrograd, Ivanovo-Voznesensk, Kharkov and Riga, as well as by the Duma Bolshevik deputies.
Warned by an agent provocateur the police swooped down on Ozerki when the conference had just completed its work. During the search of G. I. Petrovsky, A. Y. Badayev and other Duma Bolshevik deputies, the police found Lenin's theses on the war and the newspaper Sotsial-Demokrat No. 33, which carried the manifesto of the Central Committee of the R.S.D.L.P. "The War and Russian Social-Democracy". All participants in the conference were arrested, but the Duma Bolshevik deputies, who enjoyed parliamentary immunity, escaped arrest. Two days later, however, they too were arrested, tried and exiled for life to Eastern Siberia. Lenin devoted to the trial of the Bolshevik deputies the article "What Has Been Revealed by the Trial of the Russian Social-Democratic Labour Duma Group", which was published in Sotsial-Demokrat No. 40, March 29, 1915 (see this volume, pp. 171-77).
Excerpt from Lenin, Left-Wing Communism, An Infantile Disorder, 1920
Internet source: http://www.marxists.org/archive/lenin/works/1920/lwc/ch05.htm
... the rapid alternation of legal and illegal work, which made it necessary to keep the general staff—the leaders—under cover and cloak them in the greatest secrecy, sometimes gave rise to extremely dangerous consequences. The worst of these was that in 1912 the agent provocateur Malinovsky got into the Bolshevik Central Committee. He betrayed scores and scores of the best and most loyal comrades, caused them to be sentenced to penal servitude, and hastened the death of many of them. That he did not cause still greater harm was due to the correct balance between legal and illegal work. As member of the Party’s Central Committee and Duma deputy, Malinovsky was forced, in order to gain our confidence, to help us establish legal daily papers, which even under tsarism were able to wage a struggle against the Menshevik opportunism and to spread the fundamentals of Bolshevism in a suitably disguised form. While, with one hand, Malinovsky sent scores and scores of the finest Bolsheviks to penal servitude and death, he was obliged, with the other, to assist in the education of scores and scores of thousands of new Bolsheviks through the medium of the legal press. Those German (and also British, American, French and Italian) comrades who are faced with the task of learning how to conduct revolutionary work within the reactionary trade unions would do well to give serious thought to this fact. *3
In many countries, including the most advanced, the bourgeoisie are undoubtedly sending agents provocateurs into the Communist parties and will continue to do so. A skilful combining of illegal and legal work is one of the ways to combat this danger.
Excerpt from Lenin, The Declaration of Our Group in the Duma, 1906
Internet source: http://www.marxists.org/archive/lenin/works/1906/jun/22.htm
"The victory of the people is not far distant. The cause of freedom is in reliable hands. The proletariat is at its post, mustering its forces, proudly spurning the efforts of wretched provocateurs to provoke it to fight single-handed, and uniting and rallying around itself the millions and tens of millions of the oppressed and exploited living in eternal toil and eternal poverty.