"Stepped in Bear Poop" simply descibes someone who received or is receiving a ticket from a the police as a result of speeding trap set by law enforcement to ticket speeding cars. It is commonly used among CB operators in North America.
"That speedy red car convertible finally stepped in Bear poop."
To send email from another user's account, notifying the world that this person has broken computer security policy by walking away from their computer and left it unlocked.
"Erin must have gotten sheeped! I just got an email from her saying she loved sheep and wanted to find some sailors to share them with!!"