The Politico article states:
"A milestone of sorts was reached earlier this year, when Obama, the Illinois senator whose revolutionary online fundraising has overwhelmed Clinton, filed an electronic fundraising report so large it could not be processed by popular basic spreadsheet applications like Microsoft Excel 2003 and Lotus 1-2-3. "
All true and understandable, considering the vast number of donations by individuals. The article does not say anything about any of his donations being illegal. If they were illegal, The FEC would, clearly, require that the money was returned. As for your first post, in regards to Jeanne McCurdy, her contributions thus far have been 1,050.00....as is recorded by the FEC here:
http://query.nictusa.com/cgi-bin/qind/
Further, her blog site on Obama's website states that, since the 20th of last month (when the new contributions are to be delivered to the FEC) she has managed to raise another 450.00....which makes her total 1,500.00. While that is more than I can afford to contribute, she is completely within her right to do so if she is willing and able.