Conversation so far:
What were the musical characteristics and lyrics of the band Placebo?
The band Placebo's music has typically been labeled as alternative rock.
Which other genres are mentioned regarding the band Placebo's musical characteristics and lyrics besides alternative rock?
Critics have also described the band Placebo's sound as pop punk, industrial rock, Britpop, glam rock, gothic rock, electronic rock, post-punk revival, and experimental rock.
What are other factors that affect the band Placebo's music besides what genres they are considered?
Lyrically, the band Placebo's music contains many references to drugs and LGBT themes.

Question: What substantiates this claim for their music?
Self-contained rewrite: What substantiates the claim for the band Placebo's music that it contains many references to drugs and LGBT themes?