To prevent your personal information from being used for targeted advertising and data mining, there are a few steps you can take:

1. Opt-out from online tracking – websites like Google and Facebook offer settings to opt-out of targeted ad tracking.
2. Manage your browser’s privacy settings – privacy settings in web browsers can also limit the tracking of your online activity.
3. Be aware of what you click and share – some websites contain hidden tracking features, even when you’ve opted out of it. Make sure to be aware of what content you click on and are sharing.
4. Set and monitor your privacy settings for other social media apps – some apps can store your data, which could then be collected and used to target you with ads.
5. Use a secure VPN – a virtual private network (VPN) can be used to secure your network connection and encrypt your data, making it more difficult for companies to collect your data.