Fuck, these days they probably aren't even 50%
Most figure it's even lower than that. M$ market share is only around 20%, old numbers did not include phones. When you count phones, tablets, servers, super computers, and so on, M$ is well on its way to becoming irrelevant. It's only the nasty mess and the legacy of dirty business practices that they leave behind for us.
There is so much essential functionality missing from key management and encrypted e-mail, that it is in a barely usable state. For the Brazilian government, or any government for that matter, to provide end-to-end email encrytption for their own workers, so much more needs to be done.
Name me even one mail client or plug-in that can search encrypted messages, the body not just the metadata. Or how about re-keying stored messages? Federal employees often have an obligation to archive communications, but how will that fit with the recommended practice of re-keying? The list goes on.
E-mail encryption has been rather thoroughly thought through at the protocol level (thanks, Phil!) but when it comes to how it can be made to fit in with normal workflow, practically nothing has been done yet.
Microsoft used secret APIs to give its programs an advantage over competitors. That had a big effect in the 1990's. It is apparently still going on in some things but we'll have to wait, as usual, a long time before it turns up in court records. And like before, the damage will have been done. The only way to stop it is to stop using M$ products.
You can find more like that if you wade through the material of the Comes V Microsoft case at the now archived Groklaw site. Basically anything bad that has been said about M$ and the people that work there is true.
And that was just a lame excuse. She obviously had other motives for cancelling telecommuting as there is no need for a VPN for real work. SSH does not require a VPN. Nor do version control systems (git, bzr, svn). Nor do HTTPS for the intranet or IMAPS for the mail. Not even SIP or Skype for calls needs a VPN.
VPNs only add an extra layer of complexity and add little to nothing in return. That goes double for PPTP, which is garbage.
So regardless if her telecommuters were productive or unproductive, VPN use is an irelevant metric.
Please note that the author did not mention Denyhosts since his servers run OpenBSD, which incorporates DenyHosts functionality through ''pf'', its packet filter/firewall software (see the brute-force configuration of pf for more details).
You can do the same with iptables on Linux using the module "limit". See the manual page for "iptables-extensions" for the details. DenyHosts may have it's good points, but mostly it just complicates things. There is already a lot of functionality in the packet filter that you can use, whether on Linux or BSD.
However, what I see now, in contrast to years ago, are slower paced attacks. These come in steadily but at a rate that just passes under the threshold. One of these days I ought to look at what is blocked to see if it's just the slow ones getting through or if all the probes are now timed that way.