There has always been suspicion, but nothing close to proof. Now that there is close to proof that the NSA has been inserting weaknesses for themselves (unlike the DES S-Box modifications they made which actually strengthened it) The Clipper proposal seemed to suggest the NIST/NSA was interested in strong cryptosystems with explicit, transparent backdoors, and they also had the export limitations, so many non-conspiracy theory people assumed the NSA was more interested in cryptanalyzing foreign communications and keeping our domestic cryptosystems out of foreign hands.

What used to be long held cryptoanarchist conspiracy theories are no longer so far fetched, as now the NIST/NSA is more concerned with targeting the existing communication networks of friendly western democracies/domestic intercept, on which terrorists may piggyback, instead of foreign non-aligned powers.

That is, the greatest threat is no longer foreign comm networks and cryptosystems, but domestic. We have become the adversary.

Anyway, what do you call AES? It was selected as the winner by the NIST and it has widespread industry adoption.