I would say the 'big three' on the guy's side (Rupp, Farah, Centro) are definitely on the hot sauce. The women, I dunno.
Rupp: What appears to be a steady improvement is not so. After essentially stalling at 4:00, the guy suddenly has the wheels for 3:50. He breaks records left and right, develops a kick that he never had, while completing ridiculous post-race workouts. his drop-outs and low-profile meets for record attempts and his being the most tested athlete all point toward collusion among testing body and USATF. He HAS to be protected, he's the posterboy of Nike. money, money, money
Farah: always very good, but never dominant. like rupp but to a greater degree, suddenly 'discovers' last lap speed that nobody in world can match. improvement curve at his age doesn't match with those who were blowing his doors off just years prior... the 3:28 was a little too blatant! convinced that somebody got wind of his microdosing, and he was forced to step off the track temporarily in favor of marathon.
Centro: aside from messageboard rumors, there are other indicators. doesn't make much noise until championship races. drops out of big races, looks dinged up, looks out of shape, then shows up to glide thru the rounds at worlds. occasional epidermal issues, not well liked among other elites, very confident young man + talent + will to win at all costs = exactly what Sal wants
the above three are the best our country has to offer for their respective distances, so if anybody will receive the hot sauce and the protection, it's them. I'd say the lightness, epo/cera microdosing, hgh, IGF-1 LR3 major players. also, watch interviews where these three are asked about drug use--body language very telling!!