This one also ties in a little with the recent slutwalk coverage, insomuch as it looks at how those characters were judged at the time for what they wore (and still are - in researching this I was told in no uncertain terms that you can't be a feminist and show cleavage at the same time), and that these characters themselves weren't the problem, it was more that they were the only representation of women - there was not much diversity from the standard pin up babe. Also, the "blame the character" trend rather than looking to the artists, creators, and society that formed them.
"Elasti-Girl had kicked the door open for women heroes to be treated as equals at DC, and with second wave feminism well under way, and a decade of sexual revolution behind them, it's no surprise that the 1970s saw more female characters than ever appearing in mainstream comics. However, Woman's Lib still wasn't taken very seriously by many writers, and several feminist characters failed to find an audience amongst the established comics audience.
Those women characters that were successful had two things in common: a passionate desire to be treated as equals, and either a care-not attitude about skimpy clothing, or downright pleasure in flashing their tits and asses. At a time when feminists were seen as "bitches", and feminism itself treated as a passing fad, a good cleavage has been described as the sugar that helped the medicine of progression go down.
"Why you little chauvinistic piglet! I thought you understood... I'm my own woman!""
Read more: Women in Comics: Red Sonja and Power Girl - A New Hope?
As ever there was so much more I wanted to include! I'd have to write a book I think to get everything interesting in there I think, heh.
Warning for the link being rather boobtastic, and some mild nudity.