Twitter suspended Travel Ad Network's Twitter account "due to violation of Twitter's trademark policy."
Twitter's trademark policy states, in part:

What is a Trademark Policy Violation on Twitter? Using a company or business name, logo, or other trademark-protected materials in a manner that may mislead or confuse others with regard to its brand or business affiliation may be considered a trademark policy violation.
Travel Ad Network (TAN) is enmeshed in a trademark dispute with Travel Spike, which sued TAN over the issue.
Both companies run travel ad networks and the smaller company, Travel Spike, secured trademark registration for the Travel Ad Network name from the US Patent and Trademark Office in February 2011.
TAN is in the process of rebranding as Travora Media and both its Travel Ad Network and Travora Media websites have "Redecorating" signs posted on their homepages, which note that the company is "reinventing, rebranding and rebuilding."
TAN brought in a new CEO, Nan-Kirsten Forte, this summer and is in the process of transforming the company into a travel news information brand.