Russ Tice, a Bush-era NSA whistleblower, claims Obama's phones were tapped by the NSA starting in 2004 [1]. If true, questions would be raised. Could they have some leverage on him? That's just speculation though, and wouldn't give Obama an excuse for supporting the illegal [2] NSA programs.
[1] http://www.huffingtonpost.com/2013/06/20/russ-tice-nsa-obama...
[2] http://www.reuters.com/article/2015/05/07/us-usa-security-ns...