"Trial courts are granted great discretion in deciding whether or not to revoke probation. " (People v. Kelly (2007) 154 Cal.App.4th 961, 965.) "A court may revoke probation 'if the interests of justice so require and the court, in its judgment, has reason to believe from the report of the probation officer or otherwise that the person has violated any of the conditions of his or her probation . . . .' 'As the language of Penal Code section 1203.2 would suggest, the determination whether to . . . revoke probation is largely discretionary.' 'The facts supporting revocation of probation may be proven by a preponderance of the evidence.' However, the evidence must support a conclusion the probationer's conduct constituted a willful violation of the terms and conditions of probation. " (People v. Galvan (2007) 155 Cal.App.4th 978, 981-982; 1203.2, subd. (a).) "Trial courts are granted great discretion in deciding whether or not to revoke probation. " (People v. Kelly (2007) 154 Cal.App.4th 961, 965.) "A court may revoke probation 'if the interests of justice so require and the court, in its judgment, has reason to believe from the report of the probation officer or otherwise that the person has violated any of the conditions of his or her probation . . . .' 'As the language of section 1203.2 would suggest, the determination whether to . . . revoke probation is largely discretionary.' 'The facts supporting revocation of probation may be proven by a preponderance of the evidence.' " (People v. Galvan (2007) 155 Cal.App.4th 978, 981-982; 1203.2, subd. (a).) Moreover, only in a very extreme case should a reviewing court interfere with the discretion of the trial court in the matter of revoking probation. (People v. Rodriguez (1990) 51 Cal.3d 437, 443.) Section 1203.2, subdivisions (a) and (b) and case law precedent expressly authorize the use of hearsay testimony in a revocation proceeding. (People v. Burden (1980) 105 Cal.App.3d 917, 921.) "As long as hearsay testimony bears a substantial degree of trustworthiness it may legitimately be used at a probation revocation proceeding. In general, the court will find hearsay evidence trustworthy when there are sufficient 'indicia of reliability.' Such a determination rests within the discretion of the trial court and will not be disturbed on appeal absent an abuse of discretion. " (People v. Brown (1989) 215 Cal.App.3d 452, 454-455.)