The various online webfonts services which now also include open fonts (like fonts under OFL) to bring added value to their existing libraries have a strong tendency to hide the authorship and licensing information as well as put up some DRM walls to make it harder to actually exercize your freedoms or using, distributing, modifying and redistributing these fonts.
The reality is that they have simply dropped open fonts into their proprietary DRM-ized workflows and not done enough due diligence or given enough respect to these authors' copyright, despite all the fancy PR and promises.
If font authors have released their work under a FSF/OSI/community-recognized copyright license then no overarching EULA or subscription agreement can prevent users (and fellow designers) from extracting these open fonts and using them accordingly. And when these online webfont hosting services start providing rich clients to connect into their libraries directly from desktops apps, the DRM scenarios are even worse: they tend not to install them in your font folder directly but into an intermediary hidden folder that you are not supposed to know about or have much control over so they can turn access to the fonts on and off as they wish.
You can understand their desire to lock up the proprietary fonts but they can't do that to the open fonts available through the same channels: in the owning versus renting dichotomy, open fonts are firmly in the camp of owning and even better being able to make it your own and redistribute the modified version. The rights granted to you by any author releasing their creation under an open license doesn't disappear when the software channel is turned off or your subscription is invalid. The whole point of releasing a font under an open license is that it's not under exclusive control any longer and the relationship between the font author(s) and the font user(s) is more direct.
The OFL FAQ is quite clear on this:
1.17 Can Font Software released under the OFL be subject to URL-based access restrictions methods or DRM (Digital Rights Management) mechanisms?
Yes, but these issues are out-of-scope for the OFL. The license itself neither encourages their use nor prohibits them since such mechanisms are not implemented in the components of the Font Software but through external software. Such restrictions are put in place for many different purposes corresponding to various usage scenarios. One common example is to limit potentially dangerous cross-site scripting attacks. However, in the spirit of libre/open fonts and unrestricted writing systems, we strongly encourage open sharing and reuse of OFL fonts, and the establishment of an environment where such restrictions are unnecessary. Note that whether you wish to use such mechanisms or you prefer not to, you must still abide by the rules set forth by the OFL when using fonts released by their authors under this license. Derivative fonts must be licensed under the OFL, even if they are part of a service for which you charge fees and/or for which access to source code is restricted. You may not sell the fonts on their own - they must be part of a larger software package, bundle or subscription plan. For example, even if the OFL font is distributed in a software package or via an online service using a DRM mechanism, the user would still have the right to extract that font, use, study, modify and redistribute it under the OFL.
1.23 Can OFL fonts be included in services that deliver fonts to the desktop from remote repositories? Even if they contain both OFL and non-OFL fonts?
Yes. Some foundries have set up services to deliver fonts to subscribers directly to desktops from their online repositories; similarly, plugins are available to preview and use fonts directly in your design tool or publishing suite. These services may mix open and restricted fonts in the same channel, however they should make a clear distinction between them to users. These services should also not hinder users (such as through DRM or obfuscation mechanisms) from extracting and using the OFL fonts in other environments, or continuing to use OFL fonts after subscription terms have ended, as those uses are specifically allowed by the OFL.
1.24 Can services that provide or distribute OFL fonts restrict my use of them?
Practically, users of Skyfonts with the Google fonts service can simply go to
~/Library/Application Support/skyfonts-google/on OSX (or
C:\Users\%username%\AppData\Roaming\skyfont-google\on Windows) and retrieve the open fonts they have synchronised.
Similarly users of Creative Cloud with Typekit desktop can go to
~/Library/Application Support/Adobe/CoreSync/plugins/livetype/.r/on OSX (or
C:\Users\%username%\AppData\Roaming\CoreSync\plugins\livetype\ron Windows) and retrieve the open fonts they have synchronised. Note the .r hidden folder and the . in front of the various fonts to hide them. You have to reveal hidden files to be able to see them.
Notice the difference between the two: Skyfonts isn't hiding their dedicated folder any longer and newer versions of the desktop client even provide a menu entry "Reveal in Finder", Typekit Desktop still hides fonts and gives them an arbitrary numerical filename.
Of course, users should always double-check the metadata inside a font to make sure they are not retrieving a restricted proprietary font by mistake but an open font. Various tools are available to expose the font properties. Or just open them in FontForge and go to Element -> Font Info.
Surely it would be simple for them not to apply these DRM measures to any open fonts in their catalogues and keep them in a dedicated separate folder which has no need to be hidden and could just be in the normal user font folder? Or is it because, despite all the noise about open fonts being so horribly dreadful, lots of people are finding them good and useful and they actually continue to draw in subscribers for the proprietary fonts?
Sorry but you can't have the flexibility of taking advantage of open fonts without properly propagating the rights attached to them by their original authors. OK, it's a pretty weak DRM that can be worked around but it's still something that goes against the wishes of original authors and the general spirit of open fonts. If you want complete control and exclusivity then pay the authors the corresponding price and don't just leech off their open fonts without keeping them open. So, please drop that obfuscation trick and give these fonts the place they deserve in your font catalogues. Everybody will benefit.