A huge post was made about this not long ago...
Hillary Clinton is now infamous for taking tens of millions of dollars from private industries actively lobbying the federal government regarding ongoing concerns, and more than a third are government contractors.
We have all heard the common refrain to excuse this apparent conflict of interest, which is to claim Clinton was simply a "private citizen" who didn't know she was running for President. In short, the story goes that she didn't officially announce, she had every right to take any amount of money from any legal entity (it was legal) as long as "what they offered" was enough to meet her top of the line speaking fees. We are told that accepting this money does not constitute a bribe, as there is no evidence it will translate into policy as President.
Sec. Clinton gave three of those speeches within 30 days of announcing her run for President. Clinton was paid $800,000 for her last three speeches before announcing just days later. Is it possible that Hillary really didn't know just these few days before announcing her candidacy that she wasn't running? Is it possible to pinpoint the day that this spur of the moment decision came to her?
In reality, The Clinton camp had already made moves in preparation for her campaign, including signing a lease on her campaign headquarters just days after her last documented speech. Based on the reporting at the time, her staff had been searching for real estate in Brooklyn while Clinton was still giving speeches. The idea that she didn't know she was running just isn't plausible. A presidential campaign of this magnitude is a massive undertaking that requires months (even years) of planning.
This issue has been swept under the rug, as if off limits for discussion. I believe it is something that just can't be ignored. This will be one of the central points of Republican attacks against Clinton if she takes the nomination. Ignoring this will only allow it to metastasize.
Edit: Additional evidence that HRC was engaged in prohibited campaign activities posted by /u/quadrilliondollars here
I'll link it if you wish to read the comments.