Yeah. Text captcha/Recaptcha can be solved by spammers. The more advanced the more cpu time it burns up but it still does little to stop them. It just makes it super inconvenient for me to solve. Sometimes they aren't even human readable.

In the worst case, there are people in poor countries solving those chaptas for relatively little money. Probably not worth for everyone, but when operating a botnet on a large scale, thats probably a pretty attractive option as well.