Cheryl and I are vehemently open-source. We share pretty much everything we create, and share it freely. However, we do get a little upset when we see things we have created out in the Internetz, attributed to someone else. And we've dealt more than once over the past couple years with very close friends who have had their work outright stolen by bands of Miniature Internet Hooligans, who have posted direct copies of our friends' work, changed the names/schools, passed it off as theirs without any attribution, and then given said friend the Who, Me? face when called out on it.
That is shady. And we don't deal in Shady in our group of friends. Don't be that guy.
If someone (like us) says "please steal this," then feel free to take it and use it for free. We (and our friends) aren't looking to get paid for these ideas. But just add a little note-- "we took this idea from..." and all will be good. And as a corollary, if you see someone unknowingly attributing some piece of work to you that you know you took from someone else, it's not a bad idea to send back a tweet saying, "actually, this was ...'s idea." That's not necessary, but it is good Teacher-Style Internet Manners.
The second is that it's often hard to remember where you got an idea. We know many ideas are amalgamations of #BetterTogether-style collaboration and "that one thing I might have partially adapted from that one lady at that one conference five years ago..." Sometimes, the antecedent of an idea escapes us, and that's fine. But we would definitely recommend saying something like "I took parts of this from..." or "I know I got this from some conference years ago, but I don't really remember..."
One of the greatest parts of Twitter (and Pinterest, and the Internet in general) is the free and open exchange of ideas. And it's totally human to get mad when someone tries to take credit for some of the hard work you've done. So, as we start finding ideas for the new year, let's be super-conscious about giving credit where credit's due.
(I took this idea from conversations with Cheryl, Karl LS, and John Stevens. If you have any questions about open-source, free-sharing resources, ask any of the three of them--they are the experts.)