To find out if your business' Website is an offender, check it against the following list of error messages and egregious requirements.
Get Adobe Reader
We've all seen the small button alongside a link for a PDF document saying users need to download Adobe Reader. Essentially, this is a free ad for Adobe. In any case, it's a lie. There are many other reader programs out there that will let users read PDFs.
In fact, I'd argue that downloading Adobe Reader is . History has shown that it can open up your computer to repeated hack attacks, seemingly taken by Adobe Reader 10.
The Free Software Foundation Europe (FSFE) has created the that lists freely-available PDF reader software for every major platform. Instead of pointing people towards Adobe, why not use one of to direct people towards PDFreaders.org instead?