Funny but true and could even invite legal action if you don't follow the guidelines. [dislaimer: I am no legal expert]
While all internet companies have extremely strict trademark guidelines before allowing other websites to use their brand names, logos, slogans or even screensots, we look at some of the very interesting guidelines issued by Microsoft, Google and Adobe:
» If you are using a Google logo on a web page, there must exist a minimum spacing of 25 pixels between each side of the logo and other graphic or textual elements on your web page. [time to brush up your HTML skills]
» If you are linking to a Microsoft Web page from your blog, you should refer to Microsoft or their product names in a plain text font and format and use appropriate wording such as "This way to Microsoft.com" or "Click here for more information on Microsoft® Office® 2007".
» Like Google, Adobe won't allow you to use their trademarks as verbs. So never write like "The image was photoshopped". Instead, write that as The image was enhanced using Adobe® Photoshop® software.
» You are not allowed to use the the Microsoft Corporate Logo on your website.
» Don’t copy or imitate Google's trade dress, including the look and feel of Google web design properties or Google brand packaging, distinctive color combinations, typography, graphic designs, product icons, or imagery associated with Google [So logos generated with Google Logo Maker are violating some laws.]
» Adobe Trademarks must never be abbreviated. You have to write "Adobe® Photoshop® CS3 ® software" instead of "PS CS3"
» Adobe trademarks must never be used in possessive form. To write something like "Photoshop's features are impressive" would be seen as a violation.
» Microsoft would want you to set their Trademarks apart from other words or nouns they modify. For example, "After installing Windows programs" is incorrect and can be framed like "After you install the Windows® operating system".
The common way to do this is to capitalize the product name and use the appropriate trademark symbol and appropriate descriptor. You may also underline, italicize, or bold the name.
» Adobe has a special logo for display on webpage which has the Adobe corporate logo plus text that says "visit adobe.com" - you cannot use any other Adobe logo to link to their website.
» Do not use any Microsoft trademark in the title of your Web site or as a second-level domain name. You may not use any Microsoft logo without a license or written specifications from Microsoft. [so if you write a review Office 2007, you are essentially violating trademark if the post title says Microsoft Office 2007 review]
Quick Tip: A symbol registered with federal government is marked with ® symbol, unregistered trademarks are marked with TM while unregistered service marks are marked with SM. A servicemark is the same as a trademark except that it identifies and distinguishes the source of a service rather than a product.
There are just some of the tradmark guidelines but should give an idea on how frequently we are violate trademark rule though it's unintentional in most cases. Still proper use of trademarks is very important and you must reference their complete guidelines before using any of their trademark symbols in your website content.
Microsoft Trademarks | Adobe Guidelines | Google Permissions