Buffett:“When Charlie and I took this job,we did not agree to put our citizenship in a blind trust.”

[spooky3]

51. It is NOT control.

The key is in "if they can convince others to follow them" -- and that is influence, not control, since others can change their minds at any time. Further, that "if" can be true for someone with one share, and false for someone with 49% of the shares. The fact that you point to Carl Icahn as a case that stands out shows how rarely those without a large proportion of shares can exercise power. Ask the directors of the large public pension systems (who often held large stakes) how much control they feel they had in the last decade or so.

Control is 51%.

In the specific case of Berkshire, obviously Buffett is close to several like-minded shareholders, so together they likely wield a lot of influence. However, this is not the issue at all relevant to the BH tax dispute, as pointed out in my other posts, and in a link I provided to a tax attorney's site. Buffett and his team don't agree that the IRS is right, and that BH owes this. As that attorney points out, until the legal dispute is resolved, BH's management has a duty NOT to pay taxes they believe are not owed.