Content Distribution Systems (CDS) are those designed to efﬁciently deliver (to interested parties) a variety of contents. CDS may be classiﬁed in two groups. The ﬁrst group (moderated) comprises the set of systems in which contents are checked against their descriptions before being published. The second group (non-moderated) is the set of systems without any kind of moderation. Since descriptions are of paramount importance to enable users to ﬁnd contents, non-moderated CDS are clearly vulnerable to malicious interferences and susceptible to content pollution. Furthermore, colluding attackers may ﬂood the system with imprecise metadata and turn the system into a useless content distribution platform. To protect the system from massive malicious behaviors and provide better Qualityof-Experience (QoE) to users, this paper presents a novel conservative strategy to mitigate collusion attacks in non-moderated CDS. The rationale behind this simple, yet very effective strategy, is to delay user’s actions and randomly authorize them. Results indicate that this “artiﬁcial delay” reduces the effect of attackers in the system and, hence, increases user’s QoE.