'Troll Trump' is a clever political donation system thought up by the Hillary Clinton 2016 campaign. Donald Trump, the Republican nominee, is known for his frequent and controversial Twitter screeds. Troll Trump lets Clinton supporters take advantage of Trump's unhinged thumbs by automatically sending donations every time he sends a tweet.
The cleverness of the Troll Trump system for the Clinton campaign is twofold. For one, Trump tweets voraciously -- it's one of the ways that he has been able to gather such an ardent following. According to CNET, Trump's official account has tweeted 80 times within the past day, not including retweets. That means a lot of donations for Clinton.
Secondly, it's reasonable to assume that a donation to Hillary is bad for the Trump campaign. Thus, if Trump realize that his tweets directly fund Hillary, he might become inclined to tweet less.