Please can anyone explain what this means in articles??

[Radi0noise]

I see it all the time, I thought it was in speech where someone left a word out but this doesn't make any sense.

I don't understand the question.

It's a quotation

I would assume in that case that the actual quotation used a slightly different word or was the second part of a longer sentence so the [W] was added to make sense of it. It could have been something like 'he' or 'she' originally and they changed it to first person

The square brackets show something has been added - here it will be the upper-case W. The original wasn't at the beginning of a sentence

The square brackets?

It means they’ve changed the quote. It originally started ‘we’, and they’ve changed it to We with a capital letter.

What they're quoting is from the middle of a sentence, so the w would be lowercase in the original context, but they're using it at the start of a sentence so emphasising the fact it's changed from the initial sentence, if that makes sense.

It’s quoting from mid-sentence, so in the original the ‘w’ would not be capitalised. So the full quote might have been something like, ‘When we researched, we found…’

They’ve given it a capital in the article to make it correctly punctuated, and indicate this with ‘[W]e…’

It's a sentence fragment that didn't start with "we" so they have imposed the capitalisation of the W with the [] characters.

Quite a few cross posts

As an aside... imposing correct punctuation on spoken speech is a hassle. People very often do not speak in complete sentences.