Brand reputation nightmare: Trump attacks on Twitter, and his followers pile on

* Companies that get in Trump's crosshairs see immediate negative sentiment on Twitter
* Examples include Boeing, Ford, GM, and Carrier

We've just reported that when CEOs meet with President-elect Donald Trump, they almost always see their stock pop. But a reverse effect is also true: When a company gets in Trump's Twitter crosshairs, it immediately sees the rest of the twittersphere join in the attack.

Social intelligence firm Brandwatch analyzed corporate Twitter accounts and their community sentiment, both before and after Trump directly took them on. Some recent examples include Boeing, General Motors, Ford and United Technologies' Carrier. Trump's negative tweets inspired many other tweeters to get mad as well. Look at some of these charts measuring the reaction.

The day before Boeing was attacked, Brandwatch's data showed 73 percent of mentions were positive. That basically flipped the next day, going to 68 percent negative.

Trump posted this tweet:

Boeing's mentions on the social messaging platform soared to more than 241,000 — a massive spike of nearly 5,000 percent. And almost all of it was negative (represented in red below):

No different was the trend for GM. After Trump posted this tweet:

...GM's mentions jumped 452 percent on Jan. 3, again mostly negative:

In Ford's case, he tweeted about the automaker on Nov. 17, Jan. 3 and Jan. 4. The same increase in mentions happened. And here's the drop in sentiment between Jan. 2 and 3:

Trump posted about Carrier on Dec. 1, including on Instagram, and the company saw another immediate decline in sentiment.

Note that in Carrier's case the drop wasn't as dramatic perhaps because Trump had already been attacking the company for months during the campaign season.

In all the examples, it's clear how just a few words from Trump can excite thousands of others to pile on.

Trump's press conferences tend to jump from topic to topic (on Wednesday, he criticized Lockheed Martin and pharmaceutical companies), but Twitter is a much more limited platform that forces the president-elect to focus on a single subject. As a result, those 140-character messages can pack a lot of punch against an unlucky company.

"There was too much subject matter in the press conference to really dwell on his Lockheed and pharma comments," said Kellan Terry, lead analyst for U.S. political data at Brandwatch. "On Twitter, he only has enough characters to call out one subject or brand."