Pando wrote an article named After Google bought Nest, it removed one of the company’s biggest competitors from search results showing how Vivint was removed from Google shortly after Google acquired Nest.
Matt Cutts, Google's head of search spam called this "silly," in a Hacker News thread. In fact, he said the reason they were removed was because they participated in guest blog link spamming. Matt said, Google penalized them in November 2013, well before they acquired Nest in January 2014.
Here is Matt's response:
It's a shame that Pando's inquiry didn't make it to me, because the suggestion that Google took action on vivint.com because it was somehow related to Nest is silly. As part of a crackdown on a spammy blog posting network, we took action on vivint.com--along with hundreds of other sites at the same time that were attempting to spam search results.
We took action on vivint.com because it was spamming with low-quality or spam articles like...[removed, see hacker news for the links]
and a bunch more links, not to mention 25,000+ links from a site with a paid relationship where the links should have been nofollowed.
When we took webspam action, we alerted Vivint via a notice in Webmaster Tools about unnatural links to their site. And when Vivint had done sufficient work to clean up the spammy links, we granted their reconsideration request. This had nothing whatsoever to do with Nest. The webspam team caught Vivint spamming. We held them (along with many other sites using the same spammy guest post network) accountable until they cleaned the spam up. That's all.
In this case, we started dissecting this particular spammy guest blog posting network in November of 2013, and Google didn't acquire of Nest until January of 2014. So Vivint was link spamming (and was caught by the webspam team for spamming) before Google even acquired Nest.
You can then see Matt and the author of the Pando arguing on Twitter: