we're not making any money off these siggys so even if it's copyright infringment it is hard to prove the commercial loss (unless you wanna use the rl court of law to sue for sirius credits )
1. No, sigs with characters are visual representations (normally celebrities etc) of the character we're playing in the game. (Hence role play)
2. Some images are completely user-created but yeah they are taken off websites that allow their use for other matters. Stock images etc obviously may be copyright but good luck getting sued for using a picture that may not even be very recognisable in the finished result. The only money we make from them is in-game Sirius Credits.
If the original creators of the imagery didn't want others to use it, it would not be publicly displayed and/or would have a watermark on it.
Makc, stop being inflammatory. You're not hepatitis.
I source mine from the internet in no specific fashion; what I use as a search string depends on what I envisage my character to be. Copyright infringement isn't an issue for a variety of reasons I can't summon the effort to list.