Looks like there isn't a limitation for how many times a user can tap/click on the heart for articles in the resources section.
OS: Android 5.1, Windows 7, iOS 8.2
Browser: Chrome (stock browser), FireFox, Dolphin browser (all latest builds), Win7 Chrome, iOS Safari
Page tested: http://shescoding-wamuq6fved.elasticbeanstalk.com/resources