What we found
Opera Browser: DOpera's parent company ran predatory lending apps in Kenya, India, and Nigeria charging up to 438% interest.
A 2020 Hindenburg Research investigation found Opera was operating predatory lending apps in Africa and South Asia — OKash, OPay, CashBean — that charged interest rates up to 438% APR, used aggressive debt collection tactics including contacting borrowers' phone contacts to shame them, and harvested personal data from phones. Google removed several of these apps from the Play Store.
Google Chrome: DChrome tags you with a permanent ID on install.
Chrome assigns a unique client ID on installation that persists across sessions and is sent to Google with every sync, crash report, and usage metric. Combined with Google account sign-in (prompted aggressively), this creates a permanent identity linking all your browsing to your real name, email, and Google advertising profile.
Apple Safari: DSafari sends every URL you visit to Google for 'safe browsing' checks.
Safari sends URLs to Google Safe Browsing for phishing checks — and in China, to Tencent Safe Browsing. Apple didn't clearly disclose the Tencent data sharing until researchers discovered it in 2019. Your 'private' browser is sending your browsing data to Google and, if you're in China, to a company subject to China's National Intelligence Law.
Brave Browser: DThe 'privacy browser' was caught secretly adding its own referral codes to crypto exchange URLs.
In June 2020, Brave was caught injecting affiliate referral codes into cryptocurrency URLs — adding Brave's referral link to Binance, Coinbase, Ledger, and Trezor URLs. Users typing a crypto exchange URL got silently redirected through Brave's affiliate link, earning Brave commission. CEO Brendan Eich apologised and called it 'a mistake' but the code was intentional.
Microsoft Edge: DAcademic research proved Edge is the least private browser you can use — worse than Chrome.
Trinity College Dublin research ranked Edge as the LEAST PRIVATE major browser — worse than Chrome, Firefox, Safari, and Brave. Edge sends a persistent hardware UUID to Microsoft that cannot be disabled or reset. It phones home on first launch before any user consent. It was ranked alongside Yandex (Russian) in the worst privacy tier.