I too would like to know what the thought behind this question is. They are a well established company that runs 2FA and awesome phone apis / systems for thousands of startups and large companies in a field that is high barrier of entry (less competition) and predictable profits since they meter their usage.

The only thing I can think of is if a competitor enters the space and blows them away. In which case, there is your answer, you go to whomever blew them away.

I can't imagine a lawsuits or something like that taking them down at this point. They have been around too long, it would have happened already.