A clickwrap contract is generally considered legally binding. If your ToS is written such that the terms can’t be changed for previously-collected data and that

A clickwrap contract is generally considered legally binding. If your ToS is written such that the terms can’t be changed for previously-collected data and that changes of control and asset transfers will also contain this clause, if the company or an acquirer did so, users would sue. If you wanted to give users more litigation power, explicitly state that class actions are permitted. Now, if an acquirer changed the ToS for data collected after the acquisition, that’s a totally different story, but it wouldn’t be retroactive to data collected under the prior ToS. Finally, if your concern is that commercial contracts aren’t enforceable, that’s a much tougher problem to solve.