NuGet Package Explorer respects user's privacy and it does not collect any personal information from user without explicitly asking for user's consent.
OS information and IP address
When NuGet Package Explorer makes web requests to http://nuget.org to retrieve NuGet packages data, it includes user's machine's OS information in the User-Agent header. The author of NuGet Package Explorer does not have access to this information, but the website http://nuget.org does and it logs this information. The website will also log user's IP address. Again, the author of NuGet Package Explorer does not have access to this data.
3rd-party package source