For the most part they can't. That's why this deal came out at a 25% bump over where the share price was when the deal was announced. This bump is intended to

For the most part they can't. That's why this deal came out at a 25% bump over where the share price was when the deal was announced. This bump is intended to entice shareholders to vote for it. From the shareholders perspective DELL US Equity has been in a downward slide for the past year and only rebounded with this news, so if they don't take the deal then they can probably expect the share price to fall from almost 14 back to under 10 pretty much instantly. To prevent a very small minority from stopping the will of a large majority once the deal has an overwellimng majority( I think its 95% but I might be wrong on the exact value), they can then force the remainder to take the deal. This might seem like a bad deal for the hold outs but if this type of provision wasn't' enabled then no company could ever go private as there would always be that one person who holds onto a single share just to be a pain in the ass:)