In the context of official plugin repository this is very explicitly forbidden by the guidelines (emphasis mine):
7. No “phoning home” without user’s informed consent. This seemingly simple rule actually covers several different aspects:
- No unauthorized collection of user data. For example, sending the admin’s email address back to your own servers without permission of the user is not allowed; but asking the user for an email address and collecting if they choose to submit it is fine.
Other than that it will risk you reputation (imagine what user will really like discovering you did it?) and might have legal implications.
Related Posts:
- Difference Between Filter and Action Hooks?
- How many times will this code run? (or, how rich is grandma?)
- add_action hook for completely new post?
- Admin settings update updating every time home page is hit?
- WordPress Hook for user register
- Global Objects and Public Methods
- Using filters and actions for plugin API?
- Explanation of the “posts_join” and “posts_fields” filter hooks?
- How do you use the plugin boilerplate loader class to hook actions and filters?
- Does WP fire delete_post when trashed posts are automatically deleted?
- Why does do_action pass a blank string as the first parameter if no $arg is set?
- How to add a link to WordPress Plugin install Listing
- Call activation hook multiple times
- What’s the difference between hooks, filters and actions? [duplicate]
- Two-step login process – Is it possible?
- How to check if certain plugin exists and in expected version
- How can I hook into existing WordPress Bulk actions?
- Get returned variable from a function to add_shortcode function
- Earliest WP Hook to Safely and Reliably Redirect
- Define a function outside a class and call the function using action or filter hook
- Is it possible to modify the media library admin screen?
- What function to hook for changes made in status and visibility of a post
- Can I differentiate between “Delete Post Permanently” and “Empty Trash” and do something for each accordingly?
- Synchronize Custom post type tags to WordPress default posts tags
- Order of Operation for these three hooks
- Modifying values with add_action to be sent to db
- unable to stop loop when using wp_insert_post with publish_post hook
- save_post hook not triggered in WP v3.6.1
- Hook into theme-switching later than `setup_theme`
- Is it possible to delay execution of shortcode output callback?
- WordPress Ajax callback function from plugin – OOP
- Hook to get image filename when it is uploaded
- How to display a message about updates in the plugin list
- Why my database table not created on activation?
- How to delete an user including data from custom database tables
- Act on user meta updated, but only once
- Is there any way to allow a plugin to write over a previous version?
- Should action callbacks start with a verb?
- Execute Hook on the footer or header after activating a plugin
- What filter should I use to insert a button inside on Media>Add New
- best practice for query string values – get_query_var always empty for my value supplied in query string
- get_current_screen() return null
- Modifying meta tags after doing ajax call in plugin
- how to add custom functionality after woocommerce place order button
- How to use a hook to override an update_post_meta call in a plugin?
- External Authentication, session_tokens not destroyed on logout
- Conditional hook based on the core function that is calling it
- correct way to call javascript into hook function
- Prefixing plugin hooks (actions/filters) with a wrapper class or functions
- Send push when new post is published in a certain category
- Force HTTPS 301 redirect with hook
- use of do_action() without any functions attached
- How dynamic action login_form_{action} is working
- What action hook can I use to add a JavaScript to a page post using a theme template that is not including get_header() nor get_footer()?
- How to get all queries’s results after they have executed?
- Plugin uninstall function is not working
- Odd map_meta_cap $args on post edit — sometimes integer, sometimes string
- How can I create a custom plugin that allows anonymous users to signup without registering?
- hook filter after the_content on a specific page
- Bind a function with its own argument to show something dynamically after every content
- What’s the hook for filtering every texts of site?
- Hook add_attachment error
- Associate multiple email addresses with the same user account, so they can log in with either
- Run command “composer install” when activating wordpress plugin
- Update variable value via add_filter
- Custom filter not working
- hook update_option/updated_option empty $old_value and $value
- Configure WordPress to Generate Scheme-less Relative URLs
- How to find list of all functions bind to a particular hook from my plugin?
- Ajax +wordpress onClick link redirect to new page and create html content
- How to replace settings in WordPress plugin from a theme
- Creating posts with links from a txt file
- Action / Hook when a new plugin is added
- apply_filters() and call_user_func() to define and call a function outside a class
- Getting Post ID at “stylesheet” and “template” hooks
- Is there any way to get post meta from publish_post hook?
- Problem in plugin debuging in wordpress
- WordPress Plugin Boilerplate – add actions and/or filters based on user’s role
- OOP development and hooks
- Plugin Development – Call to undefined function comment_exists()
- Add_action not calling callback function
- Prevent plugin activation and add admin notice
- how to retrieve post_id under woocommerce_add_to_cart_validation hook?
- add_option_{$option} action hook not being called
- Function not working on any file other than the main plugin file
- Multi hook deploiement
- Can I use a hook other than ‘init’ to handle form submissions?
- Template file structure , wordpress hook for altering the template
- woocommerce single product page hook not working
- How can I set a dynamic value for post_updated_messages based on return value of post_updated?
- What is the use of wp_schedule_event hook?
- How do I replace title with my plugin?
- Looking for Hook that is fired after a plugin or wp upgrade is installed/updated
- Woocommerce: block user removing cart item
- Insert plugin html content to a specific spot in the frontpage
- How can I get a plugin to hook ‘dbdelta_queries’ — a filter used during version update?
- Send retrieve password notification email with custom HTML email template
- get_term_by() returning null on plugin
- Ninja Forms: Front-End Forms, Post ID?
- Execute callback after REST API request completes + Response is sent