In IBM, if you do manage to find and get an alternate position, they then target that group to lose a position because they've already factored the cost takeout into financials. So someone else then gets the chop instead.
Nowadays the rumor is that managers are given a heads up cuts are coming, the jobs disappear from Blue pages until after the cull then advertised again when it's 'safe' that they won't be hiring someone on the firing line.