A colloquial pronoun meaning 'they' or 'those guys,' used in familiar or slightly derogatory contexts; informal and sometimes disrespectful.
そいつら、また遅刻してきたよ。
Those guys are late again.
あの店の店員、そいつらの態度がひどかった。
The clerks at that shop — those guys had terrible attitudes.
会議中に『そいつらの案は通らない』と彼は言った。
He said during the meeting, 'Those guys' proposal won't pass.'