Both sides do it
"Both sides do it" (BSDI) is a phrase often used in logically fallacious arguments of various sorts.
At the simplest level, BSDI is often an attempt to justify or excuse the bad actions of one party by stating that the other party commits those same actions; this is a form of the two wrongs fallacy.
On a more subtle level, BSDI may be an attempt to draw an equivalence between the wrong acts of two (or more) parties by stating that they have both engaged in one or more specific wrong acts while ignoring or avoiding the fact that one party has actually committed those acts far more than the other – a false equivalence.
Specific usages include: