Anyone who promised to provide someone anything in return for buying may have done something illegal, but anyone who shared their genuinely held beliefs on what would happen in the future did not do anything illegal unless they are a market broker etc.

And, anyone who bought shares or told someone to buy shares with the intent of driving up the price also did something illegal - but it's something that is done constantly and considered a fundamental part of the market, either as an attack on a company in the classic hedge fund short->bankruptcy or, more benignly, like buying up shares of a takeover target slowly so people don't notice you are interested and buy it, which would raise the price.