Police officers all over the country are flying a flag or wearing patches of the following flag.
- Isn't this considered desecration of the flag under 18 U.S. Code § 700?
That statute, which was struck down by the Supreme Court in US v. Eichman, 496 U.S. 310, does not define desecration. Case law on point is not forthcoming since there is no enforceable law on the topic and as long as the First Amendment holds, we can't test laws prohibiting flag desecration. The general meaning of the word is to treat disrespectfully, irreverently, or profanely, and that clearly is not the case in the present usage. A different statute yet to be written might outlaw "any modifications of the flag" (and would suffer the same fate as 18 USC 700), which could be technically violated in the application of a thin blue line to a flag.
The law you mentioned on flags covers the normal US flag. It has nothing to do with the flag made up by police officers.
18 U.S. Code § 700. Desecration of the flag of the United States; penalties. Whoever knowingly mutilates, defaces, physically defiles, burns, maintains on the floor or ground, or tramples upon any flag of the United States shall be fined under this title or imprisoned for not more than one year, or both.
The flag used by police officers and the US flag are different things, even though the one used by the police is clearly based on the US flag. The law, therefore, does not apply to the one used by police.