I think it helps to know the history of the word Internet .
When computers were first connected together the resulting configuration was called a network .
Later people connected networks together.
That was called an internet .
Eventually most of the networks in the world were connected into one large internet that became known simply as the Internet .
In other words, there is a technical distinction between an internet and the Internet .
For what it is worth, my iPad wants me to capitalize Internet .
english.stackexchange.com/users/858/Kevin Lawrence
The fact that Web is short for World Wide Web , Sir Tim's wonderful invention, makes me think that Web should be capitalized too.
english.stackexchange.com/users/858/Kevin Lawrence
It's a matter of style.
The Guardian style guide uses lowercase: internet net, web, world wide web web, webpage, website, world wide web .
is there at least some consensus among the more popular style guides/dictionaries on this?
Not really.
Wikipedia has a page on the topic, Internet capitalization conventions , with a section on usage: Examples of media publications and news outlets that capitalize the term include The New York Times, the Associated Press, Time , and The Times of India .
In addition, many peer-reviewed journals and professional publications such as Communications of the ACM capitalize "Internet", and this style guideline is also specified by the American Psychological Association in its electronic media spelling guide.
More recently, a significant number of publications have switched to not capitalizing the noun " internet .
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Among them are The Economist, the Financial Times , The Times , the Guardian , the Observer and the Sydney Morning Herald .
As of 2011, most publications using "internet" appear to be located outside of North America, but the gap is closing.
Wired News , an American news source, adopted the lower-case spelling in 2004.
Around April 2010, CNN shifted its house style to adopt the lowercase spelling.
Wired has a 2004 piece on their decision to use internet, web and net .
Pick your own style and be consistent.
english.stackexchange.com/users/9001/Hugo
Regarding Internet, the Wikipedia disambiguation page mentions:
The Internet is a worldwide publicly accessible system of interconnected computer networks.
Where not capitalized, internet can refer to any internetwork .
You could apply the same reasoning for Web (World Wide Web) as opposed to any "web".
Although there is still the debate about Web site vs. "website" ;) If you consider proper noun as referring to "specific people, places, or things", Internet and "the Web" do qualify for their capitalize letter.
english.stackexchange.com/users/110/VonC
Wired magazine has a feature article on exactly this question , with reasons to support answers both ways, and in short it depends on your context and audience.
However, it concludes that the lowercase version will eventually win the day.
english.stackexchange.com/users/115786/WBT
My reasoning is that there is really only one network named Internet - therefore it's the Internet, while "web" is a more generic term, meaning any network (but probably referring to YouTube anyway ;).
english.stackexchange.com/users/44/analytik
I would say that it is becoming less and less common to write "Internet", as if it were a proper noun.
Indeed, the use of the phrasing "the internet" tends to indicate that "internet" is not a proper noun, because if it were, the word "the" would be redundant, and we would happily (still) refer to the internet as simply "Internet" (which used to be an accepted style, but will likely look odd to any reader not versed in the history of the internet).
The proportion of people who are familiar with the origin of "the internet" as a proper noun, or indeed to who understand that the phenomenological features of the internet qualify it as being capable of having a proper noun, seems to be dwindling.
My guess is that most people think of the internet as being like the telephone system or the air - a thing that lacks either unity, number, or identity.
english.stackexchange.com/users/6067/Marcin
There seems to be some inconsistency on whether people capitalize the words  internet  and  web  (as in  World Wide Web ) as proper nouns. What is the official ruling on when or if these words should be capitalized?  Obviously, I am not asking about when they are the first word in a sentence or in the title of a book or other publication.   Example:     "The  web  is the most commonly known  feature of the  Internet ."
Should the words "internet" and "web" be capitalized?
english.stackexchange.com
<nouns><capitalization><internet>
english.stackexchange.com/questions/644
english.stackexchange.com/users/179/JohnFx
The answer to this question will be subjective, although some people and devices will insist that the capitalised version is correct. That being said, many style guides and publications have recently switched to using the non-capitalised version. Although the upper case should be used in that the word is actually a proper noun, it is becoming less common in practice.
The answer to this question will be subjective, although some people and devices will insist that the capitalised version is correct. That being said, many style guides and publications have recently switched to using the non-capitalised version. It's a matter of style. The Guardian style guide uses lowercase.   In addition, many peer-reviewed journals and professional publications such as  Communications of the ACM  capitalize "Internet", and this style guideline is also specified by the American Psychological Association in its electronic media spelling guide.  More recently, a significant number of publications have switched to not capitalizing the noun " internet, e.g., around April 2010, CNN shifted its house style to adopt the lowercase spelling.   It is becoming less and less common to write "Internet", as if it were a proper noun.
This may be a matter of style. The Guardian style guide uses lowercase for internet, net, web, world wide web, webpage and website.   However, as Web  is short for  World Wide Web , some maintain that  Web  should be capitalized. Whilst it is generally considered that lowercase writing of "internet" and "web" is becoming more common, the answer to this question will largely depend on your own style, context and audience. Some people will argue that Web should be capitalized.
The word "Internet" is capitalised when it refers to the World Wide Web rather than a smaller internet. World Wide Web should also be capitalized as it is a proper noun. It is a matter of style. It varies - recently the lower case rendition has become more common. Technically it should be with a capital "I" but it is up to you. The lower case is getting more common. As there is only one Internet we should use upper case. It is becoming less common to use the upper case.
It's a matter of style. The Guardian style guide uses lowercase.    In addition, many peer-reviewed journals and professional publications such as  Communications of the ACM  capitalize "Internet", and this style guideline is also specified by the American Psychological Association in its electronic media spelling guide.   More recently, a significant number of publications have switched to not capitalizing the noun " internet, e.g., around April 2010, CNN shifted its house style to adopt the lowercase spelling.    It is becoming less and less common to write "Internet", as if it were a proper noun.
The answer to this question will depend on style, context and audience. It is generally agreed that lowercase writing of the words "internet" and "web" is becoming more common. Some people would say that Web should be capitalized.