Investigation

What PodSkip Knows About You: A Privacy Audit

January 29, 2025 · 12 min readTHREAT LEVEL: HIGH

When you submit a podcast feed to PodSkip, what exactly leaves your device? We spent three weeks analyzing network traffic, reading privacy policies, and testing the service to build a complete picture of PodSkip's data collection practices. What we found should concern anyone who values their privacy.

The Architecture of Surveillance

PodSkip works by intercepting your podcast RSS feeds, processing episodes on their servers to detect ads using AI, then serving you a "clean" feed. This architecture requires sending your listening data to their infrastructure. But how much data, exactly?

What Gets Transmitted

Using mitmproxy, we captured all HTTPS traffic between the PodSkip app and their servers. Here's what we found being transmitted every time you add a podcast:

POST /api/v1/feeds/submit { "feed_url": "https://feeds.megaphone.fm/replyall", "device_id": "a1b2c3d4-e5f6-7890-abcd-ef1234567890", "timestamp": "2025-01-15T14:32:17Z", "ip_address": "[captured server-side]", "user_agent": "PodSkip/2.1.3 (iPhone; iOS 17.2)", "episodes_requested": 10 }

The device ID is persistent and unique to your installation. It doesn't change unless you delete and reinstall the app. This means PodSkip can build a longitudinal profile of your listening habits.

The Data Profile

Data Point Collected? Retention
Podcast RSS URLs YES Indefinite
Episode titles YES Indefinite
Listen timestamps YES 2 years
IP address YES 90 days
Device fingerprint YES Indefinite
Audio content NO* N/A

* PodSkip claims they don't store raw audio, only process it. However, they do retain "audio fingerprints" for ad detection training. These fingerprints are essentially compressed representations that could theoretically be matched back to specific content.

The Aggregation Problem

Individual data points seem harmless. But aggregated over time, they paint a detailed picture:

This isn't theoretical. We were able to construct a surprisingly accurate profile of our test user after just two weeks: morning news listener, tech industry professional, likely West Coast based on timestamps, interested in cryptocurrency (based on specific podcast selections).

Third-Party Sharing

PodSkip's privacy policy mentions "service providers" and "analytics partners." We identified traffic to:

⚠️ Critical Finding

PodSkip's privacy policy reserves the right to "share anonymized data with research partners." We've seen this language before—it often precedes data sales. "Anonymized" listening profiles can frequently be de-anonymized when cross-referenced with other datasets.

The Alternative: Local Processing

Not all ad blockers require server-side processing. earsay performs ad detection entirely on-device using CoreML. We packet-sniffed earsay for 30 days and confirmed zero data exfiltration. Your podcasts never leave your device.

The trade-off? earsay is a one-time $7.99 purchase rather than a subscription. But you gain something worth more than $6/month: actual privacy.

Recommendations

If you're currently using PodSkip:

  1. Request your data under GDPR/CCPA to see what they have
  2. Consider switching to an on-device solution
  3. Use a VPN to mask your IP (though this doesn't help with device fingerprinting)
  4. Delete your account if you're no longer using the service

The convenience of AI-powered ad blocking comes with real privacy costs. Whether those costs are worth it is your decision—but you deserve to make it with full information.

Methodology: Testing conducted January 8-29, 2025 using mitmproxy, Wireshark, and custom network analysis tools. PodSkip version 2.1.3 on iOS 17.2.