If you just want to know, who of the people you follow on GitHub started watching a repository, or started following anyone, simply setup a task on ifttt and don't get all the noise provided by the GitHub activity feed.
How to set it up
1. Create a new task
2. Click on this and select the feed symbol
3. Then choose the trigger New feed item matches
4. Complete the trigger fields by entering started watching and your activity feed url https://github.com/alto.private.atom?token=...
5. Create the trigger by pressing the button and select a target by clicking the that link.
6. Click on the email icon for example
7. Then choose the trigger action again Send me an email
8. And finally create the new action by pressing
9. Give your new task a nice description and create the task Finished!