That string of typographic symbols that substitute for swearing in cartoons? It's called a grawlix.
The term is grawlix, and it looks to have been coined by Beetle Bailey cartoonist Mort Walker around 1964. Though it's yet to gain admission to the Oxford English Dictionary, OED Editor-at-Large Jesse Sheidlower describes it as "undeniably useful, certainly a word, and one that I'd love to see used more."
Well, @#$%&?!, that's cool.
English Sentences Without Overt Grammatical Subjects, or the grammar of swearing. "Chomsky observes that the adverbial elements of (39)-(42) are outside of the verb phrase and that only elements within the verb phrase play a role in strict subcategorization of verbs. That principle would clearly be violated if fuck were a verb."
The origins and common usage of British swear words. "Both Oxford and London boasted districts called 'Gropecunte Lane', in reference to the prostitutes that worked there. The Oxford lane was later renamed the slightly less-contentious Magpie Lane, while London's version retained a sense of euphemism when it was changed to 'Threadneedle Street'. Records do not show whether it was a decision of intentional irony that eventually placed the Bank of England there."