As much as we want to see him locked away forever, there is a set of laws that we must follow. If bail is something that is allowed for charges such as his, than this must be offered. His crime was not something that was considered violent, so it is unlikely that, while one bail, he will hurt anyone, and therefore, should be allowed free on bail.
It was right for Martin Shkreli to be released from custody on bail because that follows the laws of the United States justice system. Because was charged with fraud and not a violent crime, his being released from custody does not endanger anyone else, so it would be unjust to hold him without bail.
His face is known and his ego is large. He wouldn't go into hiding or try to run. The judges and courts are meant to be lenient but fair. Popular opinion does not advocate a harsher sentence, no matter how angry people are in general. He will face the charges because he will believe to beat the charge.
Martin Shkreli committed a henious crime, and should not have been released on bail no matter how much money he can afford to pay. Raising the price to unreasonable rates on a drug that many people need to survive is inhumane, unethical and horrific. In my opinion, it is attempted murder. Shkreli should remain in prison until his trial, and should receive no less than a lifetime sentence for his crime.