An FEC complaint has been filed against non-candidate candidate Fred Dalton Thompson.

The complaint alleges...

It is clear that he has violated 11 CFR 100.72, the "testing the waters" provision of FEC law. Accordingly, his failure to file disclosure reports violates the law, and the Commission should demand full disclosure of Mr. Thompson's campaign fund raising and expenditures, as well as penalize Mr. Thompson for his willful violation of the law.

[extensive snip]

Mr. Thompson had approximately $2.8 million in his campaign account after the IRS filing. This fact also clearly indicates that he did not intend to use this money for 'exploring' a possible candidacy. Otherwise, it would have been spent on exploratory activities, especially given the documentation of his impending announcement of candidacy.

Jake Tapper explains:

The rule is pretty simple. If you spend more than $5,000 on campaign activities, you're a candidate, whether or not you've officially declared.

OK, then.