Is all the content here on SO CC licensed?
I have seen some snippets of code which weren't officially CC licensed.
What if poster doesn't note it is licensed.
Can I get in trouble for using it in my projects?
From the footer:
The license that applies is CC-Attribution (BY)-Share Alike (SA), with special Stack Exchange attribution rules. This only applies to questions, answers, comments, tag wikis, and privilege descriptions, but does not apply to SE trademarks and text, such as site logos, which are the property of Stack Exchange, Inc.