An IP user on the English Wikipedia reports the following slightly alarming bug:
"After I edited text near a link, "♙♙♙♙♙♙♙" characters started appearing around once a second, and I couldn't stop them or delete them."
Based on another bug report left a few minutes later by the same user they were using MobileSafari on iPad 2 with iOS 6.1.3
I can't replicate this in Firefox on a Linux PC and don't have an iPad to test on.
Platform: Tablet PC