Here is a complete list of all the top-level execs who have bailed out of Twitter

Twitter might be acquired by Disney. Or Salesforce. Maybe Google.

At least, those are the rumours. But as the alleged talks continue, analysts are examining the issues that have to be overcome in various potential matchups. Jason Bazinet and his team at Citi Research published a note to clients yesterday suggesting that one of the more "troubling" issues for any company that wants to own Twitter is the dwindling number of people in top management who regard Twitter as their life's mission.

Current CEO Jack Dorsey is a founder of the company, of course, but he only works there part-time (his other job is running Square). And he has left the company before, in 2008.

In its lifetime, "Twitter has gone through four CEO's in nine years," the Citi crew says. "While the CEO turnover is troubling, press reports suggest a high level of departures are taking place deeper into the organization structure. This includes senior roles, product development roles and engineering roles."

Twenty-seven senior executives have left Twitter since 2007. First,here are the reigns of the various CEOs:

And here are the various top managers:

On the latter list, the most serious sections are the product chiefs and the engineering chiefs, near the bottom. Those are the people who can actually build and ship new features, functions and apps. Twitter has lost 13 of those in the last two years alone.

Disclosure: This author owns Twitter stock.