if you mean takeover by one man, it is possible but not that probable. No one owns 70M hive, and to buy that off the market would be really hard if not impossible and most probably really expensive as the price would go up a lot.
Real option that will most probably not happen is Exchanges teaming up and powering up users funds. when 30 days wait period to vote witnesses is added exchanges powering up to try that would be in the domain of crazy, because they would have a public shit show for that 30 days, and no one wants that.