Social media platforms, including Twitter (now X), have policies in place to maintain a safe and trustworthy advertising environment. However, the extent to which these policies are adhered to and enforced remains a subject of interest and concern. We present the first large-scale audit of advertising on Twitter focusing on compliance with the platform's advertising policies, particularly those related to political and adult content. We investigate the compliance of advertisements on Twitter with the platform's stated policies and the impact of recent acquisition on the advertising activity of the platform. By analyzing 34K advertisements from ~6M tweets, collected over six months, we find evidence of widespread noncompliance with Twitter's political and adult content advertising policies suggesting a lack of effective ad content moderation. We also find that Elon Musk's acquisition of Twitter had a noticeable impact on the advertising landscape, with most existing advertisers either completely stopping their advertising activity or reducing it. Major brands decreased their advertising on Twitter, suggesting a negative immediate effect on the platform's advertising revenue. Our findings underscore the importance of external audits to monitor compliance and improve transparency in online advertising.

翻译：社交媒体平台，包括推特（现更名为X），均制定了相关政策以维护安全可信的广告环境。然而，这些政策在多大程度上得到遵守和执行仍是备受关注和令人担忧的议题。我们首次开展针对推特广告的大规模审计研究，重点关注平台广告政策（尤其是涉及政治与成人内容的相关政策）的合规情况。我们系统考察了推特广告与其官方政策的一致性，以及近期收购事件对平台广告活动的影响。通过分析六个月间收集的约600万条推文中包含的3.4万条广告，我们发现存在广泛违反推特政治与成人内容广告政策的现象，这表明平台缺乏有效的广告内容审核机制。研究同时发现，埃隆·马斯克收购推特对广告生态产生了显著影响——大多数现有广告主要么完全停止广告投放，要么大幅削减投放规模。主要品牌减少推特广告支出的趋势，表明收购事件对平台广告收入产生了直接的负面冲击。本研究成果凸显了外部审计机制在监督政策合规、提升在线广告透明度方面的重要价值。