It means "as it was originally written".  In other words, the person who is quoting the original is saying that they are not the author of the spelling mistake or typo (or textspeak).  

Well, according to Wiki:

The Latin adverb sic ("thus"; in full: sic erat scriptum, "thus was it written") added immediately after a quoted word or phrase (or a longer piece of text), indicates that the quotation has been transcribed exactly as found in the original source, complete with any erroneous spelling or other nonstandard presentation.

According to me, it can also be used to show the writer thinks they are smarter than the quotee (is that a word?) and has picked up their error 😛

It means as written..spelling mistakes, syntax errors and all.

The sentence you have quoted has "by" spelt incorrectly and "u" instead of you.

Also no apostrophes in won"t.

It's used when quoting someone where there is a error in  spelling.

It means that the word or sentence that has errors in it is  copied exactly as the original  author wrote it.  that the error was not made by the person quoting it.

Thanks now I know.

When I have asked other people they usually say "You kown" and I didn't.

waaaaay to slow.........;\

totally sic man! 

a thread where 5 people in a row all agree on something LOL

It's not over yet crikey, the day is still young :^O